Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Kenji Kaneko Last modified date:2021.04.06

Professor / Structural Materials Engineering / Department of Materials Science and Engineering / Faculty of Engineering


Papers
1. Ogo, Seiji; Ando, Tatsuya; Le Tu Thi Minh; Mori, Yuki; Matsumoto, Takahiro; Yatabe, Takeshi; Yoon, Ki-Seok; Sato, Yukio; Hibino, Takashi; Kaneko, Kenji, A NiRhS fuel cell catalyst - lessons from hydrogenase, CHEMICAL COMMUNICATIONS, 10.1039/d0cc04789a, 56, 79, 11787-11790, 2020.10.
2. Baba, Norio; Kaneko, Kenji; Baba, Misuzu, Novel nonlinear reconstruction method with grey-level quantisation units for electron tomography, SCIENTIFIC REPORTS, 10.1038/s41598-020-77156-1, 10, 1, 2020.11.
3. Abe, H; Murata, K; Fukui, T; Moon, WJ; Kaneko, K; Naito, M, Influence of Aging Products on Tensile Deformation Behavior of Al-0.62 mass%Mg-0.32 mass%Si Alloy, THIN SOLID FILMS, 10.2320/jinstmet.J2014063, 79, 5, 273-279.
4. Kousei Sato, Kenji Kaneko, Toru Hara, Yasuhito Kawahara, Jun ichi Hamada, Chikako Takushima, Ryo Teranishi, Plan-view characterization of intergranular precipitates on grain boundaries by combination of FIB lift out method and TEM analyses
A case study in austenitic stainless steel, Micron, 10.1016/j.micron.2020.102927, 138, 2020.11, A new characterization method is proposed to study intergranular precipitates of polycrystalline material in the planar manner. A dual beam focused ion beam (FIB) - scanning electron microscopy (SEM) was applied to fabricate thin FIB lamella with a grain boundary parallel to the lamella to investigate for transmission electron microscopy (TEM). Distributions, microstructures and compositions of intergranular precipitates of austenitic stainless steel were then examined by TEM, scanning transmission electron microscopy (STEM), and energy dispersive X-ray spectroscopy (EDS). This plan-view microstructural characterization methods would play important roles in the case of materials where the intergranular precipitates play key roles for their physical and chemical properties..
5. Syota Fujinaka, Yukio Sato, Ryo Teranishi, Kenji Kaneko, Understanding of scanning-system distortions of atomic-scale scanning transmission electron microscopy images for accurate lattice parameter measurements, Journal of Materials Science, 10.1007/s10853-020-04602-w, 55, 19, 8123-8133, 2020.07, Atomic-scale scanning transmission electron microscopy (STEM) imaging has opened up the possibility of studying the local lattice parameters of crystalline materials. To ensure more accurate measurements, low-frequency distortions of the images should be properly calibrated, which requires a better understanding of their causes. Although the major possible causes are sample drift and the scanning systems of microscopes, their effects are intricate because the rates of sample drifts differ in respective measurements. In the present study, low-frequency distortions of STEM images and their dependence on scan rotations were evaluated by measuring the lattice parameters of a reference specimen, strontium titanate. The distortions due to sample drifts and the scanning system of a microscope were separately calculated and corrected using affine transformations. In the as-observed images, the length scales in the x and y directions were underestimated by 0.4–1.2% and 2.7–3.6%, respectively, with shear distortions of 0.6°–1.2°, and the magnitudes of the underestimation and shear distortions were dependent on the scan rotations. On the basis of these findings, a methodology was proposed for the correction of distortions for accurate measurement of the lattice parameters of materials..
6. Pawan Kumar, Kartikey Thakar, Navneet Chandra Verma, Jayeeta Biswas, Takuya Maeda, Ahin Roy, Kenji Kaneko, Chayan Kanti Nandi, Saurabh Lodha, Viswanath Balakrishnan, Polymorphic In-Plane Heterostructures of Monolayer WS2 for Light-Triggered Field-Effect Transistors, ACS Applied Nano Materials, 10.1021/acsanm.0c00027, 3, 4, 3750-3759, 2020.04, The realization of next-generation transition-metal dichalcogenide based nanoscale devices demands stringent control over coherent in-plane heterostructures of atomically thin monolayers with exceptional properties. In this paper, we report atmospheric-pressure chemical vapor deposition growth of large-domain, coherent polymorphic in-plane heterostructures of monolayer WS2 on a SiO2/Si substrate with intriguing optical and electronic properties. The formation of in-plane heterostructures with 1H and 1T polymorphs was extensively analyzed using a variety of spectroscopic as well as microscopic techniques, along with lifetime luminescence imaging. High-angle annular dark-field scanning transmission electron microscopy revealed coexistence of the heterophases in monolayer WS2 heterostructures. Back-gated photoconductivity measurements in nanoscale field-effect-transistor device geometry and the rational design of a WS2 heterostructure pattern demonstrate optoelectronic applications..
7. Yukio Sato, Mai Aoki, Ryo Teranishi, Kenji Kaneko, Masaki Takesada, Hiroki Moriwake, Hiroshi Takashima, Yukiya Hakuta, Atomic-Scale Observation of Titanium-Ion Shifts in Barium Titanate Nanoparticles
Implications for Ferroelectric Applications, ACS Applied Nano Materials, 10.1021/acsanm.9b01221, 2, 9, 5761-5768, 2019.09, Ferroelectric nanoparticles (NPs) have attracted considerable attention owing to their size effect on the ferroelectricity and their possible application toward future electronic devices such as multilayer ceramic capacitors and ferroelectric random access memory. The ferroelectricity disappears for NPs smaller than the critical size, which has been an obstacle for the development of materials. Although the fundamental mechanisms of the size effect should be clarified to overcome this problem, the understanding has been made ambiguous by the fact that NPs of different morphologies prepared by different methods exhibit various critical sizes, which indicates that more investigations should be conducted on the appearance/disappearance of ferroelectricity in NPs. To gain insight into the appearance of ferroelectricity, atomic-scale characterizations are beneficial because the ferroelectricity is closely related to the atomistic structures. In the present study, atomic-scale scanning transmission electron microscopy (STEM) observations were conducted for a barium titanate NP prepared by a hydrothermal method, using a supercritical continuous-flow reaction system. Two STEM images were obtained with different foci: one was observed by focusing an electron probe on the top surface of the NP and the other on the middle. Different directions of titanium-ion shifts were observed near the top surface and in the middle of the NP, which could be explained by STEM image simulations using structural models with the presence of an additional region with a different titanium-ion-shift direction. The present findings imply that this NP should exhibit the ferroelectricity and contains two regions of different polarization directions..
8. Ryo Teranishi, Kazuya Hiramatsu, Syotaro Yasuyama, Tomohiro Miyajima, Yukio Sato, Kenji Kaneko, Satoshi Awaji, Akiyoshi Matsumoto, Masayoshi Inoue, Superconducting Joint of GdBa2Cu3Oy Coated Conductors by Crystallization of an Additionally Deposited Precursor Layer, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2019.2902693, 29, 5, 2019.08, A superconducting joint of REBa2Cu3Oy (REBCO) coated conductors (CCs) has been demanded strongly to fabricate long length CCs for high field magnet applications such as nuclear magnetic resonance and magnetic resonance imaging. In the previous reports of superconducting joint, specimens of REBCO CCs were jointed via melting REBCO phases or via solid state diffusion of REBCO phases. In our study, we propose a new method of joint for REBCO CCs. A precursor layer is additionally deposited on GdBCO CC by a metal organic deposition process, and then two pieces of them are stuck together face-To-face and crystallized the precursor to form 123 phase under mechanical pressure in an oxygen atmosphere. The microstructures and temperature dependence of resistance of the jointed sample are characterized by a cross-sectional transmission electron microscopy (TEM) and a four-probe method, respectively. As a result, TEM observation reveals that two CCs are jointed together without formation of secondary phases at the joint interface. Also, temperature dependence of resistance shows Tc onset and Tc zero of 93 K and 82 K, respectively. Consequently, a superconducting joint has been completed successfully. The concept of this method is combining film growth and solid-state diffusion for the additionally deposited precursor layers..
9. Minoru Ochi, Kousei Sato, Ryo Teranishi, Yukio Sato, Jun Ichi Hamada, Chikako Takushima, Toru Hara, Kenji Kaneko, Nanostructural analyses of Intra- And intergranular precipitates in high-temperature heat-treated nitrogen-added austenitic stainless steel, Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan, 10.2355/tetsutohagane.TETSU-2018-067, 105, 4, 8-15, 2019.04, More than one thousand intragranular and intergranular precipitates of nitrogen-added austenitic stainless steel, SUSXM15J1, were characterized by FIB-SEM serial-sectioning tomography, by conventional transmission electron microscopy (TEM) and by scanning transmission electron microscopy (STEM). All of intragranular precipitates were found nitrided to form dichromium nitride, Cr2N, Two types of intergranular precipitates were found Cr2N and Cr3Ni2Si(N), and some of them were grown and jointed due to the additional heat treatment during the tensile test at 1173 K. which probably contributed to its high-temperature strength..
10. Yuki Koshino, Yasuhiro Aruga, Junpei Mukai, Kenji Kaneko, Relationship among elongation, work hardening behavior and dislocation characteristics of AlMgSi series alloys, Materials Transactions, 10.2320/matertrans.L-M2018845, 60, 1, 68-73, 2019.01, Dislocation multiplication and dynamic recovery in the tensile deformed AlMgSiCu alloys were characterized by transmission electron microscope (TEM), to reveal the correlation between the dislocation characteristics and the elongation behaviors. 6016 (Al0.4%Mg1.0%Si0.2%Cu (mass%)) and 6014 (Al0.6%Mg0.7%Si0.1%Cu) alloys were aged at 363 K for 18 ks after solution treated and quenched into water. The maximum n-value of 6016 alloy was found higher than that in the 6014 alloy. The n-value reduction rate after reaching its maximum of 6016 alloy was found smaller than that of 6014 alloy. Furthermore, the dislocation multiplication on {111} plane and the formation of dislocation band were formed in 6016 alloy with more than 10% of tensile deformation. Therefore, the slip lines observed by scanning electron microscope (SEM) are finely formed. The homogeneous dispersion of slip lines are probably the cause of higher elongation of 6016 alloy than that of 6014 alloy. It is believed that suppression of the cross slip dislocation may contribute to a higher elongation. [doi:10.2320/matertrans.L-M2018845].
11. Tomohiro Miyajima, Ryo Teranishi, Syotaro Yasuyama, Yukio Sato, Kenji Kaneko, Valery Petrykin, Sergey Lee, Tatsunori Okada, Satoshi Awaji, Akiyoshi Matsumoto, Influence of joint pressure on superconducting and mechanical properties for jointed GdBa2Cu3Oy coated conductors via precursor films, Japanese Journal of Applied Physics, 10.7567/1347-4065/ab0727, 58, 5, 2019.01, There has been demand to lengthen superconducting joints of REBa2Cu3Oy coated conductors to realize magnet applications. In this work, jointed samples of GdBa2Cu3Oy coated conductors were prepared by crystallizing precursor films deposited by a pulsed laser deposition method under mechanical pressures, and influence of the pressures on superconducting and mechanical properties were investigated. While areal fraction and shearing stress of the joints were increased by increasing the pressure, superconducting properties were degraded. X-ray diffraction analysis indicated that the degradation was due to the formation of a secondary phase and decrease of oxygen contents in GdBa2Cu3Oy.
12. Yuki Koshino, Yasuhiro Aruga, Takuya Maeda, Kenji Kaneko, Influences of solute concentration on uniform elongation and dislocation characteristics of Al-Mg and Al-Si alloys, Keikinzoku/Journal of Japan Institute of Light Metals, 10.2464/jilm.69.180, 69, 3, 180-185, 2019.01, Influences of solute atoms and their contents on the uniform elongation were investigated using Al-Mg and Al-Si alloys respectively. Dislocation characteristics of both alloys were examined by X-ray diffractometry and transmission electron microscopy. In the case of solute concentration ranging between 0.3 and 1.6 (mass%), it was found that the increase of solute concentration caused the decrease of the uniform elongation for the case of Al-Mg alloys, whereas the increase of that for the case of Al-Si alloys. It was suggested that the solute Mg in aluminum caused a strong interaction on dislocation with comparison to the solute Si, which probably caused the large increase of dislocation density during the tensile deformation. It is considered that the solute Si has stronger effect of decreasing the stacking fault energy of the aluminum alloy than the solute Mg. Thus, as for Al-Si alloys, the increase of the work-hardenability and the uniform elongation may occur by retardation of the dynamic recovery during the tensile deformation..
13. Tomohiro Miyajima, Ryo Teranishi, Syotaro Yasuyama, Yukio Sato, Kenji Kaneko, Takuya Maeda, Minoru Ochi, Kazuya Hiramatsu, Miyuki Nakamura, Valery Petrykin, Sergey Lee, Tatsunori Okada, Satoshi Awaji, Microstructures of superconducting joint between GdBa2Cu3Oy-coated conductors via additionally deposited precursor films, Japanese Journal of Applied Physics, 10.7567/1347-4065/ab0f23, 58, 5, 2019.01, Superconducting joints have been demanded to lengthen REBa2Cu3O y -coated conductors for electrical power applications. In this study, we propose a new joint method for GdBa2Cu3O y -coated conductors via crystallizing precursor films additionally deposited on the conductors. Two GdBa2Cu3O y -coated conductors with precursor films were placed in a face-to-face manner in a furnace, then they were crystallized under mechanical pressure to joint them. A superconducting joint was achieved with a high critical temperature of 90.8 K. Microstructural observation by a transmission electron microscope revealed that there were only a few pores at the joint boundary without a secondary phase having c-axis-oriented GdBa2Cu3O y.
14. Yukio Sato, Ryuki Miyauchi, Mai Aoki, Syota Fujinaka, Ryo Teranishi, Kenji Kaneko, Large Electric-Field-Induced Strain Close to the Surface in Barium Titanate Studied by Atomic-Scale In Situ Electron Microscopy, Physica Status Solidi - Rapid Research Letters, 10.1002/pssr.201900488, 2019.01, Measuring the lattice parameters of crystalline materials under an electric field at the nanoscale improves the understanding of how electronics operate. Herein, atomic-scale in situ electron microscopy is used to measure the lattice parameters near the surface of barium titanate under an electric field, which is varied to understand how it changes the lattice parameters. Applying an electric field along the a axis does not cause domain switching. Instead, as the electric field increases, so as well does the c-axis lattice parameter (c), whereas the a-axis lattice parameter (a) remains nearly constant. The c value increases as much as 4.5 − 7.0 pm at ±13.8 kV cm−1, which is beyond the measurement precision. The increases are localized near the surface and the c value recovers slowly, which suggests that the observed phenomena are related to surface effects and slow processes. These results cannot be explained by electrostrain, even when considering additional effects such as mechanical constraint, inclination of electric field, and surface and size effects. Instead, the results are explained using a combination of Joule heating, vacancy introduction, and surface effects..
15. Takuya Maeda, Yasuhito Kawahara, Keisuke Kinoshita, Hideaki Sawada, Jun Takahashi, Ryo Teranishi, Kenji Kaneko, An answer to the carbon cluster in low-temperature aged ferritic low-carbon steel, Materials Characterization, 10.1016/j.matchar.2019.110006, 2019.01, The morphology and crystal structure of the carbon cluster in a low-temperature aged low-carbon ferritic steel were clarified by performing conventional and in-situ TEM, and atomically-resolved ADF-STEM observation. The carbon cluster grow parallel to <001> direction of the matrix, whose morphology was presumed to be either disk or plate. Lattice constant of the carbon cluster was measured by peak fitting of atomic columns observed by ADF-STEM. The result clarified that the structure of the carbon cluster was martensite-like body-centered tetragonal (bct) structure. This martensite-like bct structure suggested that the carbon cluster was supersaturated with carbon atoms occupying specific octahedral sites..
16. Kevin Pappert, Kateryna Loza, Meital Shviro, Ulrich Hagemann, Marc Heggen, Rafal E. Dunin-Borkowski, Roland Schierholz, Takuya Maeda, Kenji Kaneko, Matthias Epple, Nanoscopic Porous Iridium/Iridium Dioxide Superstructures (15 nm)
Synthesis and Thermal Conversion by In Situ Transmission Electron Microscopy, Chemistry - A European Journal, 10.1002/chem.201901623, 25, 47, 11048-11057, 2019.01, Porous particle superstructures of about 15 nm diameter, consisting of ultrasmall nanoparticles of iridium and iridium dioxide, are prepared through the reduction of sodium hexachloridoiridate(+IV) with sodium citrate/sodium borohydride in water. The water-dispersible porous particles contain about 20 wt % poly(N-vinylpyrrolidone) (PVP), which was added for colloidal stabilization. High-resolution transmission electron microscopy confirms the presence of both iridium and iridium dioxide primary particles (1–2 nm) in each porous superstructure. The internal porosity (≈58 vol%) is demonstrated by electron tomography. In situ transmission electron microscopy up to 1000 °C under oxygen, nitrogen, argon/hydrogen (all at 1 bar), and vacuum shows that the porous particles undergo sintering and subsequent compaction upon heating, a process that starts at around 250 °C and is completed at around 800 °C. Finally, well-crystalline iridium dioxide is obtained under all four environments. The catalytic activity of the as-prepared porous superstructures in electrochemical water splitting (oxygen evolution reaction; OER) is reduced considerably upon heating owing to sintering of the pores and loss of internal surface area..
17. Ken Takata, Kohsaku Ushioda, Kenji Kaneko, Ryutaro Akiyoshi, Ken ichi Ikeda, Satoshi Hata, Hideharu Nakashima, Solid solution hardening in supersaturated AlMgSi alloy, Materials Transactions, 10.2320/matertrans.MT-M2019190, 60, 12, 2525-2529, 2019.01, The yield strength and work hardening of AlMgSi alloys are related to the concentration of solute atoms. This study was carried out to clarify the effect of two kinds of solute atoms on these properties in terms of a linear combination of contributions from a solid solution. Tensile tests were conducted with Al and with Al0.62Mg0.32Si, Al0.65Mg0.81Si, Al2.4Mg, and Al4.4Mg (mass%) alloys in solid solution. Work hardening was analyzed using the KocksMecking model, yielding two parameters which indicate the storage and recovery of dislocations in the material. The yield strength could not be expressed as a linear combination of solute atom concentrations, but the amount of dislocation storage and dynamic recovery could be expressed as such linear combinations. In the high-strain region, the KocksMecking model no longer applies, and the maximum stress at which the model failed increased with increasing concentrations of solute atoms. It is generally known that an interaction between strain fields around solute atoms and quenched-in vacancies can affect the yield strength owing to dislocation motion and that these atoms can retard the development of microstructures in high-strain regions. A linear combination of contributions from solid solutions is possible only for the storage and recovery of dislocations in the low-strain region..
18. Takuya Maeda, Kenji Kaneko, Takuya Namba, Yuki Koshino, Yukio Sato, Ryo Teranishi, Yasuhiro Aruga, Structural and compositional study of precipitates in under-aged Cu-added Al-Mg-Si alloy, Scientific Reports, 10.1038/s41598-018-35134-8, 8, 1, 2018.12, Atomic scale characterization of fine precipitates in an under-aged Cu added Al-Mg-Si alloy was carried out by combination of atomically-resolved annular dark-field scanning transmission electron microscopy and energy dispersive X-ray spectroscopy. Two types of precipitates were observed in the alloy. In the case of ordered β” precipitates, β” was proposed as Mg5-xAl2+xSi4 (x ≈ 1) with solute Cu atoms replacing Al site of β” precipitate. In the case of disordered precipitates, the precipitates were found to consist of β” sub-unit cells, three-fold symmetric structure without Cu atoms, Cu containing structures termed as “Cu sub-unit cluster”, and Q’ sub-unit cells. Among these structures, the morphologies of three-fold symmetric structure without Cu atoms, Cu sub-unit cluster, and Q’ sub-unit cell were almost the same, so that these structures should be the clusters of Q’ phase. Since the areal density, length and diameter of precipitates were almost equal between Cu free Al-Mg-Si alloy and Cu added Al-Mg-Si alloy, the increase of hardness by Cu addition should be due to the precipitation of Cu related precipitates, such as Cu sub-unit clusters and Q’ sub-unit cells..
19. Pawan Kumar, Dipanwita Chatterjee, Takuya Maeda, Ahin Roy, Kenji Kaneko, Viswanath Balakrishnan, Scalable faceted voids with luminescent enhanced edges in WS2 monolayers, Nanoscale, 10.1039/c8nr02246a, 10, 34, 16321-16331, 2018.09, A scalable approach is needed in the formation of atomically flat edges with specific terminations to enhance local properties for optoelectronic, nanophotonic and energy applications. We demonstrate point defect clustering-driven faceted void formations with luminescent enhanced edges in WS2 monolayers during large-scale CVD growth and controlled annealing. With the aid of aberration-corrected scanning transmission electron microscopy (AC-STEM) high angle annular dark field (HAADF) imaging, we probed atomic terminations of S and W to explain observed luminescence enhancement in alternate edges. Faceted void formation in monolayer WS2 was found to be sensitive to annealing temperature, time, gas environment and precursor supply. Our observations of areal coverage evolution over time revealed competition between monolayer WS2 growth and void formation at 850 °C. While the initial stage was dominated by monolayer growth, defect generation and void growth dominated at later stages and provided an optimum processing window for monolayer WS2 as well as faceted void growth. Growth of faceted voids not only followed the geometry of monolayer facets but also showed similar atomic terminations at the edges and thus enabled local manipulation of photoluminescence enhancement with an order of magnitude increase in intensity. The developed CVD processing enabled multi-fold increase in the luminescent active edge length through the formation of faceted voids within the WS2 monolayer..
20. Minoru Ochi, Kousei Sato, Ryo Teranishi, Yukio Sato, Jun Ichi Hamada, Chikako Takushima, Toru Hara, Kenji Kaneko, Nanostructural analyses of intra- and intergranular precipitates in high-temperature heat-treated nitrogen-added austenitic stainless steel, ISIJ International, 10.2355/isijinternational.ISIJINT-2017-756, 58, 8, 1459-1466, 2018.08, More than one thousand intragranular and intergranular precipitates of nitrogen-added austenitic stainless steel, SUSXM15J1, were characterized by FIB-SEM serial-sectioning tomography, by conventional transmission electron microscopy (TEM) and by scanning transmission electron microscopy (STEM). All of intragranular precipitates were found nitrided to form dichromium nitride, Cr2N, two types of intergranular precipitates were found Cr2N and Cr3Ni2Si(N), and some of them were grown and jointed due to the additional heat treatment during the tensile test at 1 173 K, which probably contributed to its high-temperature strength..
21. Ryo Teranishi, Kazuki Konya, Masayoshi Inoue, Yukio Sato, Kenji Kaneko, Teruo Izumi, Satoshi Awaji, Study of growth process for YBa2Cu3Oy Coated Conductors with BaZrO3 Flux Pinning Centers by Monitoring Electrical Conductivity, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2018.2818752, 28, 4, 2018.06, YBa2Cu3Oy (YBCO) coated conductors were prepared by a metal organic deposition method using a chemical solution with tri-fluoroacetate salts. A salt of Zr was also added into the solution to introduce BaZrO3 (BZO) flux pinning centers into the YBCO films. The solution was coated on CeO2/LaMnO3/MgO/Gd2Zr2O7/Hastelloy substrates, and the coated films were crystallized at 1053 K. In this work, an additional holding temperature step was introduced during the crystallization of the films at 873 K to miniaturize the size of BZO nanoparticles, and then the effect of the heat treatment on the electrical conductivity of the film during the crystallization was examined. It was found that the conductivity of the film with the additional holding temperature step was approximately 1.7 times higher than that of the film fabricated without the one when the film temperature reached the crystallization temperature of 1053 K. In addition, the period until the conductivity saturated was three times smaller for the film fabricated with the additional holding temperature step. These results indicate that the growth temperature of YBCO shifts down and the holding period for YBCO crystallization can be shorter by introducing an additional holding temperature step..
22. Satoshi Ohara, Tadafumi Adschiri, Minoru Miyahara, Kenji Kaneko, Akira Ohtomo, Characterization Methods for Nanostructure of Materials, Nanoparticle Technology Handbook, 10.1016/B978-0-444-64110-6.00005-6, 255-300, 2018.05, The 20th century was the so-called "age of new material synthesis" as shown in Fig. 5.1.1 (Adschiri, 2002). "Synthesis" of new substances had been essential to attain a new property for materials. However, in the recent R&D of material, keen attention is attracted on controlling material function by the material structure. Nanotechnology is a typical example of this stage of technology. In the control of material structure, "process" is regarded more important than "synthesis." For example, in the nanoparticle production, size and shape of particle significantly depend on the operating conditions of crystallization process. It was found that some semiconductor materials show strong photoluminescence and the wavelength can be controlled with its particle size ("quantum size effect"). With a same wavelength of excitation, a wide range of colors can be obtained by changing the particle size of the nanoparticles of CdSe, CdTe, CdS, etc., the so-called quantum dots (Medintz et al., 2005). Photonic crystal can be produced by self-assembly of nanomaterials (homoassembly) and the control of self-assembly phenomena is a critical issue of process design and operation. In the fabrication of ultraviolet laser (Tang et al., 1998, Kawasaki et al., 1998, Huang et al., 2001) and light-emitting diode (LED) (Tsukazaki et al., 2005) based on ZnO materials, laser molecular beam epitaxy is a powerful process to grow fine ZnO nanocrystals self-assembled and arrayed parallel on substrates. The next stage of the nanotechnology will be "programmed assembly" of nanomaterials because this is a foreseeable future target for the industries of various fields. In the device production by assembling the structured materials, "fabrication" is the key technology. Thus, science and technology for materials is being shifted from "synthesis" toward "processing" and "fabrication."..
23. Ken Ichi Ikeda, Takuya Takashita, Ryutaro Akiyoshi, Satoshi Hata, Hideharu Nakashima, Kazuhiro Yamada, Kenji Kaneko, Effects of scandium and zirconium addition on recrystallization behavior of AlMgSi alloy, Materials Transactions, 10.2320/matertrans.L-M2018802, 59, 4, 590-597, 2018.01, The effects of thermally stabilized particles on the recrystallization behavior of an AlMgSi alloy were investigated to obtain the fundamental knowledge for controlling the microstructure, texture, and mechanical properties of this alloy. In this study, the AlMgSiScZr alloy was cast, homogenized, and hot-rolled. Three types of spherical Al3(Sc, Zr) particles with L12 structure, rod-like incoherent, spherical semi-coherent, and spherical incoherent particles, were observed in a hot-rolled sample of the AlMgSiScZr alloy using transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM), and energy-dispersive X-ray spectroscopy (EDS). In addition, three-dimensional electron tomography (3D-ET) and STEM-EDS revealed that all particles have a core-shell structure with a Sc-enriched core and a Zr-enriched shell. It is considered that these particles are formed during casting, homogenized treatment, and hot rolling. The crystal orientation distribution of the sample after cold rolling indicated that the presence of Al3(Sc, Zr) particles may interfere with the recrystallization (grain growth) until 600°C. Comparison with the driving force of primary recrystallization and grain growth, and the pinning force of Al3(Sc, Zr) particles, showed that these particles mainly contribute to the suppression of grain growth. The results of an in-situ heating SEM/EBSD analysis of the cold-rolled AlMgSiScZr alloy supported this suggestion..
24. Shogo Amemori, Rakesh Kumar Gupta, Marcus Leo Böhm, James Xiao, Uyen Huynh, Tomoki Oyama, Kenji Kaneko, Akshay Rao, Nobuhiro Yanai, Nobuo Kimizuka, Hybridizing semiconductor nanocrystals with metal-organic frameworks for visible and near-infrared photon upconversion, Dalton Transactions, 10.1039/c7dt04794k, 47, 26, 8590-8594, 2018.01, Hybrid materials consisting of semiconductor nanocrystals and metal-organic frameworks (MOFs) were prepared for the first time to achieve photon upconversion based on triplet-triplet annihilation (TTA-UC) in the solid-state, which allowed TTA-UC with large anti-Stokes shifts in the visible and near-infrared regions..
25. Yuki Koshino, Yasuhiro Aruga, Junpei Mukai, Kenji Kaneko, Relationship among elongation and work hardening behavior and dislocation characteristics of Al-Mg-Si series alloys, Keikinzoku/Journal of Japan Institute of Light Metals, 10.2464/jilm.68.201, 68, 4, 201-205, 2018.01, Dislocation multiplication and dynamic recovery in the tensile deformed Al-Mg-Si-Cu alloys were characterized by transmission electron microscope (TEM), to reveal the correlation between the dislocation characteristics and the elongation behaviors. 6016 (Al-0.4%Mg-1.0%Si-0.2%Cu (mass%)) and 6014 (Al-0.6%Mg-0.7%Si-0.1%Cu) alloys were aged at 363 K for 18 ks after solution treated and quenched into water. The maximum n-value of 6016 alloy was found higher than that in the 6014 alloy. The n-value reduction rate after reaching its maximum of 6016 alloy was found smaller than that of 6014 alloy. Furthermore, the dislocation multiplication on {111} plane and the formation of dislocation band were formed in 6016 alloy with more than 10% of tensile deformation. Therefore, the slip lines observed by scanning electron microscope (SEM) are finely formed. The homogeneous dispersion of slip lines are probably the cause of higher elongation of 6016 alloy than that of 6014 alloy. It is believed that suppression of the cross slip dislocation may contribute to a higher elongation..
26. Ken Takata, Kohsaku Ushioda, Kenji Kaneko, Ryutaro Akiyoshi, Ken Ichi Ikeda, Satoshi Hata, Hideharu Nakashima, Solid solution hardening in supersaturated Al-Mg-Si alloy, Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, 10.2320/jinstmet.J2018015, 82, 8, 314-318, 2018.01, The yield strength and work hardening of Al.Mg.Si alloys are related to the concentration of solute atoms. This study was carried out to clarify the effect of two kinds of solute atoms on these properties in terms of a linear combination of contributions from a solid solution. Tensile tests were conducted with Al and with Al.0.62Mg-0.32Si, Al.0.65Mg.0.81Si, Al.2.4Mg and Al.4.4Mg (mass%) alloys in solid solution. Work hardening was analysed using the Kocks .Mecking model, yielding two parameters which indicate the storage and recovery of dislocations in the material. The yield strength could not be expressed as a linear combination of solute atom concentrations, but the amount of dislocation storage and dynamic recovery could be expressed as such linear combinations. In the high.strain region, the Kocks .Mecking model no longer applies, and the maximum stress at which the model failed increased with increasing concentrations of solute atoms. It is generally known that an interaction between strain fields around solute atoms and quenched.in vacancies can affect the yield strength owing to dislocation motion and that these atoms can retard the development of microstructure in high.strain regions. A linear combination of contributions from solid solutions is possible only for the storage and recovery of dislocations in the low.strain region..
27. Mitsuhiro Kikkawa, Takeshi Yatabe, Takahiro Matsumoto, Ki Suk Yoon, Kazuharu Suzuki, Takao Enomoto, Kenji Kaneko, Seiji Ogo, A Fusion of Biomimetic Fuel and Solar Cells Based on Hydrogenase, Photosystem II, and Cytochrome c Oxidase, ChemCatChem, 10.1002/cctc.201700995, 9, 21, 4024-4028, 2017.11, We report an Ir complex as an anode catalyst capable of switching between a hydrogenase-type fuel-cell mode and a photosystem II-type solar-cell mode. This catalyst is connected to carbon-black-supported platinum as a cathode catalyst, which reduces dioxygen in a manner analogous to cytochrome c oxidase. Together, they make a system capable of switching between the two modes..
28. Yudai Miyake, Yukio Sato, Ryo Teranishi, Kenji Kaneko, Effect of heat treatments on the microstructure and formability of Al–Mg–Mn–Sc–Zr alloy, Micron, 10.1016/j.micron.2017.07.003, 101, 151-155, 2017.10, Microstructures and formability of scandium and zirconium added Al-Mg-Mn alloy sheets with various heating conditions were examined to improve their mechanical properties. Formability of these samples were judged by the Lankford value, r-value. It was possible to fabricate mechanically balanced Al-Mg-Mn-Sc-Zr alloy with high hardness 76.2 Hv and with high formability with r = 1.2, by not only adding scandium and zirconium but also optimizing the heat treatment conditions..
29. Yukio Sato, Takashi Gondo, Hiroya Miyazaki, Ryo Teranishi, Kenji Kaneko, Electron microscopy with high accuracy and precision at atomic resolution
In-situ observation of a dielectric crystal under electric field, Applied Physics Letters, 10.1063/1.4986361, 111, 6, 2017.08, Measuring atomic positions in-situ under an external electric field can provide important insights into the structure-property relationship of electronic materials. In this paper, we demonstrate picometer level accuracy and precision of atomic positions in single-crystalline SrTiO3 under an electric field through annular dark-field scanning transmission electron microscopy. By carrying out electrical biasing in-situ electron microscopy at the atomic scale, the lattice constant was measured with a precision of 9.0 pm under an electric field of ±0.57 kV/cm. In addition, the Ti position in the SrTiO3 unit cell was measured with an accuracy of 20.0 pm at a confidence level of greater than 93%. This opens up a possibility of characterizing functional electronic devices at atomic resolution under operative conditions..
30. Yuchi Fan, Shintaro Ida, Aleksandar Tsekov Staykov, Taner Akbay, Hidehisa Hagiwara, Junko Matsuda, Kenji Kaneko, Tatsumi Ishihara, Ni-Fe Nitride Nanoplates on Nitrogen-Doped Graphene as a Synergistic Catalyst for Reversible Oxygen Evolution Reaction and Rechargeable Zn-Air Battery, Small, 10.1002/smll.201700099, 13, 25, 2017.07, Obtaining bifunctional electrocatalysts with high activity for the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) is a main hurdle in the application of rechargeable metal-air batteries. Earth-abundant 3d transition metal-based catalysts have been developed for the OER and ORR; however, most of these are based on oxides, whose insulating nature strongly restricts their catalytic performance. This study describes a metallic Ni-Fe nitride/nitrogen-doped graphene hybrid in which 2D Ni-Fe nitride nanoplates are strongly coupled with the graphene support. Electronic structure of the Ni-Fe nitride is changed by hybridizing with the nitrogen-doped graphene. The unique heterostructure of this hybrid catalyst results in very high OER activity with the lowest onset overpotential (150 mV) reported, and good ORR activity comparable to that for commercial Pt/C. The high activity and durability of this bifunctional catalyst are also confirmed in rechargeable zinc-air batteries that are stable for 180 cycles with an overall overpotential of only 0.77 V at 10 mA−2..
31. T. Maeda, Kenji Kaneko, K. Yamada, A. Roy, Yukio Sato, Ryo Teranishi, T. Kato, T. Izumi, Y. Shiohara, Nanostructural characterization of artificial pinning centers in PLD-processed REBa2Cu3O7-δ films, Ultramicroscopy, 10.1016/j.ultramic.2016.11.015, 176, 151-160, 2017.05, In the context of high temperature superconductors, pulsed laser deposition derived GdBa2Cu3O7-δ sample with BaHfO3 nanoparticles has been reported to achieve high current density and good IC-B-θ characteristics at high temperatures. Herein, we have carried out a thorough nanostrucural characterization of BaHfO3 nanoparticles embedded in GdBCO matrix using scanning transmission electron microscopy, with an emphasis on the dispersion behavior, morphologies and nanostrain, to understand the role of BaHfO3 nanoparticles..
32. Minoru Ochi, Rika Kawano, Takuya Maeda, Yukio Sato, Ryo Teranishi, Toru Hara, Masao Kikuchi, Kenji Kaneko, Three-dimensional studies of intergranular carbides in austenitic stainless steel, Microscopy (Oxford, England), 10.1093/jmicro/dfw103, 66, 2, 89-94, 2017.04, A large number of morphological studies of intergranular carbides in steels have always been carried out in two dimensions without considering their dispersion manners. In this article, focused ion beam serial-sectioning tomography was carried out to study the correlation among the grain boundary characteristics, the morphologies and the dispersions of intergranular carbides in 347 austenitic stainless steel. More than hundred intergranular carbides were characterized in three dimensions and finally classified into three different types, two types of carbides probably semi-coherent to one of the neighboring grains with plate-type morphology, and one type of carbides incoherent to both grains with rod-type morphology. In addition, the rod-type carbide was found as the largest number of carbides among three types. Since large numbers of defects, such as misfit dislocations, may be present at the grain boundaries, which can be ideal nucleation sites for intergranular rod-type carbide precipitation..
33. Ryosuke Urakami, Yukio Sato, Masayoshi Ogushi, Takeshi Nishiyama, Aoi Goto, Kazuhiro Yamada, Ryo Teranishi, Kenji Kaneko, Mikito Kitayama, Phase transformation and interface segregation behavior in Si3N4 ceramics sintered with La2O3–Lu2O3 mixed additive, Journal of the American Ceramic Society, 10.1111/jace.14663, 100, 3, 1231-1240, 2017.03, Microstructure and mechanical property of silicon nitride (Si3N4) ceramic are strongly dependent on the selection of sintering additives. When rare-earth (RE) oxide is used as the sintering additive, segregation of RE ions at interface between Si3N4 grain and intergranular glassy film (IGF) is believed to play a critical role. Although the ionic radius of RE ion is known to be an empirical parameter to modify the mechanical property, the correlation between the segregated ions and their ionic radii is still under controversy. In order to address this issue, (i) rate of α-β phase transformation and (ii) segregation behavior at the interface were studied for Si3N4 ceramics sintered using mixture of La2O3 and Lu2O3 as additives in this study. Specimens of Lu content 30% and higher exhibited lower activation energies for the α-β phase transformation as compared with those of Lu content 20% and lower. In terms of the segregation behavior, La was preferably segregated at one site and Lu at the other site along β-Si3N4/IGF interface in the specimens of Lu content 30% and higher. It is understood from these results that Lu segregation site should be more closely related with grain growth..
34. H. Horita, Ryo Teranishi, Kazuhiro Yamada, Kenji Kaneko, Yukio Sato, K. Otaguro, T. Nishiyama, T. Izumi, S. Awaji, Miniaturization of BaHfO3 nanoparticles in YBa2Cu3O y -coated conductors using a two-step heating process in the TFA-MOD method, Superconductor Science and Technology, 10.1088/1361-6668/30/2/025022, 30, 2, 2017.02, The critical current density (J c) of YBa2Cu3Oy (YBCO)-coated conductors in a magnetic field can be enhanced by the doping of flux-pinning centers in a metal organic deposition (MOD) process with trifluoroacetates (TFA). The size of these flux-pinning centers should be less than 10 nm to achieve commercial use due to the coherence length of YBCO at 77 K. In this paper, BaHfO3 (BHO) nanoparticles were introduced into YBCO films using the TFA-MOD method. Microstructures and the J c properties of the films prepared using a two-step heating process at crystallization were compared with film prepared using a conventional one-step heating process. The two-step heating process produced 15 nm average-sized BHO nanoparticles in the film compared to 19 nm nanoparticles in a film prepared using a one-step process. It was revealed that the size of nanoparticles in the films could be miniaturized by improving the heating processes in the MOD method, and the miniaturized nanoparticles could contribute to increased J c in magnetic fields. The mechanism of miniaturization is also discussed based on microstructure observations of quenched films..
35. Yusuke Kasuya, Yukio Sato, Ryosuke Urakami, Kazuhiro Yamada, Ryo Teranishi, Kenji Kaneko, Electron microscopic analysis of surface damaged layer in Pb(Mg1/3Nb2/3)O3-PbTiO3 single crystal, Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes, 10.7567/JJAP.56.010312, 56, 1, 2017.01, Single crystals of lead magnesium niobate-lead titanate, Pb (Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT), have superior dielectric and piezoelectric properties suitable for medical ultrasound imaging. Imaging devices with superior performance can be manufactured from thinner PMN-PT single crystals by mechanical dicing and/or polishing. Although it is often a concern that a damaged layer may form during the mechanical dicing and/or thinning process, the microscopic characteristics of the damaged layer have not yet been investigated in detail. In this study, the microstructural characterization of a damaged layer was investigated by transmission electron microscopy. It was found that mechanical polishing introduced dislocation near the surface of the crystal. It was also found that the domain structure was affected by the introduction of dislocation..
36. Norihiro Kanno, Jun Ichi Hamada, Kenji Kaneko, Morphology of cu particle during higherature deformation in cu-added ferritic stainless steels, Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan, 103, 9, 539-548, 2017.01, In this study, Cu-added ferritic stainless steel sheets were investigated to understand the influences of Cu contents on the higherature strength during the higherature deformation. Higherature proof stress at 700∼900°C was improved greatly by addition of more than 1% of Cu. In the case of static aging at 900°C, the rod-shaped e-Cu particles satisfed the K-S orientation relationship with the a matrix, but spherical-shaped e-Cu particles without specifc orientation relationship started appearing during the tensile deformation at 900°C. Similarly, the spherical-shaped and fne e-Cu particles were observed during the thermal fatigue process in the temperature range from 200°C to 700°C with a 50% restriction ratio. During the observation using the higherature in-situ TEM straining, it was clarifed that the e-Cu particles were divided by dislocation shearing and parts of them were found dissolved. According to the LSW theory, it was suggested that the microstructure with fne and spherical-shaped e-Cu particles was formed by the repetition of dissolution and precipitation during the higherature deformation..
37. Keita Ishiba, Takao Noguchi, Hiroaki Iguchi, Masa-Aki Morikawa, Kenji Kaneko, Nobuo Kimizuka, Photoresponsive Nanosheets of Polyoxometalates Formed by Controlled Self-Assembly Pathways, Angewandte Chemie - International Edition, 10.1002/anie.201612473, 56, 11, 2974-2978, 2017.01, Anionic Keggin polyoxometalates (POMs) and ether linkage-enriched ammonium ions spontaneously self-assemble into rectangular ultrathin nanosheets in aqueous media. The structural flexibility of the cation is essential to form oriented nanosheets; as demonstrated by single-crystal X-ray diffraction measurements. The difference in initial conditions exerts significant influence on selecting for self-assembly pathways in the energy landscape. Photoillumination of the POM sheets in pure water causes dissolution of reduced POMs, which allowed site-specific etching of nanosheets using laser scanning microscopy. By contrast, photoetching was suppressed in aqueous AgNO3 and site-selective deposition of silver nanoparticles occurred as a consequence of electron transfer from the photoreduced POMs to Ag+ ions on the nanosheet surface..
38. Ken Takata, Kohsaku Ushioda, Ryutaro Akiyoshi, Ken Ichi Ikeda, Jun Takahashi, Satoshi Hata, Kenji Kaneko, Improvement of strength-elongation balance of Al-Mg-Si sheet alloy by utilising Mg-Si cluster and its proposed mechanism, Materials Transactions, 10.2320/matertrans.M2016258, 58, 5, 728-733, 2017.01, The tensile properties of an Al-Mg-Si alloy with Mg-Si clusters were compared with those of an Al-Mg-Si alloy with β′′ precipitates of the same strength. The elongation of the alloy with Mg-Si clusters was found to be greater than that of the alloy with β′′ precipitates because of the high work hardening rate of the former alloy, particularly in the high-strain region. Decomposition of Mg-Si clusters into solute Mg and Si atoms during the tensile deformation was revealed by differential scanning calorimetry. Transmission electron microscopy revealed three types of dislocation characteristics in these alloys: homogeneous distribution of dislocations with β′′ precipitates, cell structures in the alloy with solute Mg and Si, and a combination of these two types in the alloy with Mg-Si clusters. In the case of the alloy with Mg-Si clusters, the yield strength increased significantly owing to the dislocation cutting mechanism; simultaneously, the elongation of this alloy improved greatly because of the presence of solute Mg and Si atoms formed by decomposition via plastic deformation, which were inferred to prevent dynamic recovery in the later stage of tensile deformation. Consequently, a comparison of conventional 6000 series and 7000 series Al alloys revealed that the alloy with clusters had advantages over the alloy with precipitates and the alloy with solutes in terms of the balance between strength and elongation..
39. Ryo Teranishi, Kenya Otaguro, Hiroshi Horita, Kazuhiro Yamada, Kenji Kaneko, Teruo Izumi, Satoshi Awaji, Minimization of BaHfO3 Flux Pinning Centers in YBa2Cu3Oy Films by Metal Organic Deposition Process, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2016.2549863, 26, 3, 2016.04, YBCO films with BaHfO3 (BHO) nanoparticles were fabricated by a metal organic deposition method using trifluoroacetate (TFA) solution with Hf salt. The diameter of BHO nanoparticles was minimized by the additional holding temperature during the crystallization process. Critical current density (JC) in magnetic fields of YBCO films with BHO nanoparticles was higher than that of the film with BaZrO3 (BZO). Accordingly, it was revealed that BHO nanoparticles act as very effective artificial pinning centers..
40. Sumiha Ikeshita, Ansis Strodahs, Zineb Saghi, Kazuhiro Yamada, Pierre Burdet, Satoshi Hata, Ken ichi Ikeda, Paul A. Midgley, Kenji Kaneko, Hardness and microstructural variation of Al-Mg-Mn-Sc-Zr alloy, Micron, 10.1016/j.micron.2015.12.002, 82, 1-8, 2016.03, Variations of Vickers hardness were observed in Al-Mg-Mn alloy and Al-Mg-Mn-Sc-Zr alloy at different ageing times, ranging from a peak value of 81.2 HV at 54ks down to 67.4 HV at 360ks, below the initial hardness value, 71.8 HV at 0ks for the case of Al-Mg-Mn-Sc-Zr alloy. Microstructures of samples at each ageing stage were examined carefully by transmission electron microscopes (TEMs) both in two-dimensions and three-dimensions. The presence of different types, densities, and sizes of particles were observed dispersed spherical Al3Sc1-xZrx and also block-shaped Al3Sc precipitates growing along <100>Al with facets {100} and {110} of the precipitates. TEM analysis both in two-dimensions and three-dimensions, performed on various samples, confirmed the direct correlation between the hardness and the density of Al3Sc..
41. Ken Ichi Ikeda, Takuya Takashita, Ryutaro Akiyoshi, Satoshi Hata, Hideharu Nakashima, Kazuhiro Yamada, Kenji Kaneko, Effects of scandium and zirconium addition on recrystallization behavior of Al-Mg-Si alloy, Keikinzoku/Journal of Japan Institute of Light Metals, 10.2464/jilm.66.609, 66, 11, 609-616, 2016.01, The effects of thermally stabilized particles in Al-Mg-Si alloy on recrystallization behavior were investigated to obtain fundamental knowledge to control microstructure, texture and mechanical properties of this alloy. In this study, the Al-Mg-Si-Sc-Zr alloy was cast, homogenized and hot rolled. Three types of spherical Al3(Sc, Zr) particles with L12 structure: Rod-like incoherent, spherical semi-coherent and spherical incoherent particles were observed in the hot-rolled sample in the Al-Mg-Si-Sc-Zr alloy by using TEM, STEM and EDS. In addition, it was found that all particles have the core-shell structure with the core enriched with Sc and the shell enriched with Zr atoms by 3D-ET and STEM-EDS. It is considered that these particles are formed during casting, homogenized treatment and hot rolling. The results of crystal orientation distribution of annealed sample after cold rolling indicated that the presence of Al3(Sc, Zr) particles may interfere with the recrystallization (the grain growth) until 600°C. From the comparison with the driving force of primary recrystallization and grain growth, and the pinning force of Al3(Sc, Zr) particles, it was suggested that these particles mainly contribute to the suppression of grain growth. The results of in-situ heating SEM/EBSD analysis of cold rolled Al-Mg-Si-Sc-Zr alloy supported the suggestion..
42. Y. Okabe, Y. Yoshikawa, R. Kita, H. Kubo, O. Miura, K. Yamada, Kenji Kaneko, Fabrication of GdBa2Cu3Oy Films by Liquid-phase-assisted Metal-organic Deposition Using Fluorine-free Solutions, Physics Procedia, 10.1016/j.phpro.2016.04.001, 81, 101-104, 2016.01, The fabrication of GdBa2Cu3Oy (GdBCO) superconducting films by liquid-phase-assisted metal-organic deposition (LPA-MOD) was investigated as a new technique for the growth of thicker MOD films using fluorine-free solutions. A 300 nm thick GdBCO film with a strong c-axis orientation was successfully grown on a MOD-GdBCO seed layer using Gd-Ba-Cu-O solution layers. A 600 nm thick LPA-MOD GdBCO film had a critical current density (Jc) of 1.28 MA/cm2, which is higher than that of the MOD GdBCO seed layer alone..
43. Shuhei Kobayashi, Kenji Kaneko, Kazuhiro Yamada, Masao Kikuchi, Norihiro Kanno, Jun Ichi Hamada, In-situ TEM observation of the interaction between dislocations and particles of Cu-added ferritic stainless steel under high-temperature straining, ISIJ International, 10.2355/isijinternational.ISIJINT-2015-711, 56, 10, 1796-1799, 2016.01, Cu is always present in the matrix when ferritic steels were prepared from ferrous scrap. When the ferritic steels are aged thermally, Cu particles start appearing and dispersing finely and homogeneously, which may result the steels strengthened by dispersion strengthening. In this study, the interactions between Cu particles and dislocations were examined via high-temperature in-situ TEM straining. Cu-added ferritic stainless steel (Fe-18.4%Cr-1.5%Cu) was used in the present study. Specimen was aged at 1 073 K for 360 ks. Microstructure of specimen was analyzed by JEM-3200FSK and high-temperature in-situ TEM straining was conducted using JEM-1300NEF. Progressing dislocations in matrix contacted with the Cu particle at right angle. This result implies that there is an attractive interaction between dislocations and the Cu particle. Furthermore, dislocations pass through the particle after contacting it, so that the interaction with dislocations and particles should be explained by Srolovitz mechanism..
44. K. Hiramatsu, Ryo Teranishi, K. Yamada, Yukio Sato, Kenji Kaneko, Joint of REBa2Cu3O7-δ Coated Conductors Using Metal Organic Deposition, Physics Procedia, 10.1016/j.phpro.2016.04.003, 81, 109-112, 2016.01, Joint techniques connecting REBa2Cu3O7-δ(REBCO) coated conductors (CCs) are required to fabricate long length CCs and to repair locally damaged one. Two pieces of REBCO CC were attempted to be jointed using a metal organic deposition (MOD) method. The starting solution for YBCO layer was coated on GdBCO layer of CCs and calcined to fabricate precursor films, two of which were stuck together in a face to face manner, and then these films were pressurized and crystallized to joint them. Two CCs were successfully jointed together with c-axis oriented YBCO without pores and reacted phases at the joint interface..
45. Viet Ha Tran, Takeshi Yatabe, Takahiro Matsumoto, Hidetaka Nakai, Kazuharu Suzuki, Takao Enomoto, Takashi Hibino, Kenji Kaneko, Seiji Ogo, An IrSi oxide film as a highly active water-oxidation catalyst in acidic media, Chemical Communications, 10.1039/c5cc04286k, 51, 63, 12589-12592, 2015.08, We report an acid-stable Si oxide-doped Ir oxide film (IrSi oxide film), made by metal organic chemical vapour deposition (MOCVD) of an IrV complex for electrochemical water-oxidation. This is a successful improvement of catalytic ability and stability depending upon the pH of Ir oxide by doping of Si oxide. The turnover frequency (TOF) of the electrochemical water-oxidation by the IrSi oxide film is the highest of any Si oxide-doped Ir oxide materials and higher even than that of Ir oxide in acidic media..
46. H. Suzuki, R. Kita, H. Kubo, O. Miura, K. Yamada, Kenji Kaneko, Effects of Holmium Doping on the Critical Current Density in GdBa2Cu3Oy Films Fabricated by Metal-organic Deposition Using Fluorine-free Solutions, Physics Procedia, 10.1016/j.phpro.2015.05.164, 65, 133-136, 2015.01, The effects of holmium (Ho) doping on the fabrication and superconducting properties of GdBa2Cu3Oy (GdBCO) films fabricated by metal-organic deposition using 2-ethylhexanate solutions were investigated. Ho doping up to a doping level of 7.5 mol% did not affect the crystal growth and critical transition temperatures of the GdBCO films. The Ho-doped GdBCO films showed improved critical density (Jc) compared to the pure film. For 5-mol%-Ho-doped GdBCO films, the Jc at the self-magnetic field and the α value were 1.51 MA/cm2 and 0.65, respectively, while those of the pure films were 0.85 MA/cm2 and 0.69, respectively..
47. Shuhei Kobayashi, Kenji Kaneko, Kazuhiro Yamada, Masao Kikuchi, Norihiro Kanno, Jun Ichi Hamada, High-temperature in-situ TEM straining of the interaction with dislocations and particles for Cu-added ferritic stainless steel, Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan, 10.2355/tetsutohagane.101.315, 101, 6, 315-318, 2015.01, Synopsis : Cu is always present in the matrix when ferritic steels were prepared from ferrous scrap. When the ferritic steels are aged thermally, Cu precipitates start appearing and dispersing finely and homogeneously, which may result the steels strengthened by precipitation hardening. In this study, the interactions between Cu precipitates and dislocations were examined via high-temperature in-situ TEM straining. Cu-added ferritic stainless steel (Fe-18.4%Cr-1.5%Cu) was used in the present study. Specimen was aged at 1073 K for 360 ks. Microstructure of specimen was analyzed by JEM-3200FSK and high-temperature in-situ TEM straining was conducted using JEM-1300NEF. Progressing dislocations in matrix contacted with the Cu precipitate at right angle. This result implies that there is an attractive interaction between dislocations and the Cu precipitate. Furthermore, dislocations pass through the particle after contacting it, so that the interaction with dislocations and particles should be explained by Srolovitz mechanism..
48. Ken Takata, Kohsaku Ushioda, Ryutaro Akiyoshi, Ken Ichi Ikeda, Jun Takahashi, Satoshi Hata, Kenji Kaneko, Improvement of strength and elongation balance of Al-Mg-Si alloy utilizing Mg-Si cluster and its mechanism, Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, 10.2320/jinstmet.J2015026, 79, 8, 391-397, 2015.01, Tensile properties of Al-Mg-Si alloy with Mg-Si clusters was compared with that withβ precipitate with the same strength. It was found that the elongation of the alloy with Mg-Si cluster was greater than the alloy with β precipitate because of high work hardening rate, in particular at large strain region. Decomposition of Mg-Si cluster into solute Mg and Si atoms during the tensile deformation test were also shown by differential scanning calorimetry (DSC). Three types of dislocation characteristics were observed from these alloys by transmission electron microscopy (TEM), homogeneous distribution of dislocation with β precipitate, cell structure with Mg and Si in solid solution, and combination of them with Mg-Si cluster. For the case of alloy with Mg-Si cluster, the yield strength was significantly increased due to the cutting mechanism. Simultaneously, the elongation was greatly improved due to the presences of decomposed solute Mg and Si atoms with plastic strain, which are inferred to prevent dynamic recovery in the later stage of tensile test. Consequently, the alloy with clusters has advantages from both alloys with precipitates and solutes, in terms of strength and elongation balance among the conventional 6000 series and 7000 series Al alloys..
49. Ryutaro Akiyoshi, Ken Ichi Ikeda, Satoshi Hata, Hideharu Nakashima, Takeshi Kasama, Ken Takata, Jun Takahashi, Kohsaku Ushioda, Kenji Kaneko, Influence of aging products on tensile deformation behavior of Al-0.62 mass%Mg-0.32 mass%Si alloy, Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, 10.2320/jinstmet.J2014063, 79, 5, 273-279, 2015.01, Tensile tests and microstructural observations were carried out to investigate the influence of aging products on tensile deformation behavior of Al-0.62 mass%Mg-0.32 mass%Si alloy. Solution-treated alloys were aged to form needle-like β" precipitates or Mg-Si clusters. The aged alloy with β" precipitates showed higher yield stress than that with Mg-Si clusters. Transmission electron microscopy observations revealed that the β" precipitates pinned dislocations. It was suggested that the strengthening types of the alloy with β" precipitates were both Orowan and cutting mechanism, by estimating the Orowan stress and considering crystal structure of β" precipitates. In contrast, the aged alloys with Mg-Si clusters showed excellent performance of uniform elongation due to large work hardening compared to those of the alloy with β" precipitates. Dislocations in the alloy with Mg-Si clusters were wavy in morphology. The yield stress of the alloy with Mg-Si clusters was higher than that of the solution-treated alloy and much lower than the estimated Orowan stress. This result indicated that the cutting mechanism was the main strengthening type of the aged alloy with Mg-Si clusters, and this strengthening mechanism gave a good balance of strength and elongation..
50. Rika Kawano, Kenji Kaneko, Toru Hara, Kazuhiro Yamada, Yukio Sato, Kenji Higashida, Masao Kikuchi, Decorated dislocations with fine precipitates observed by FIB-SEM slice-sectioning tomography, Tetsu-To-Hagane/Journal of the Iron and Steel Institute of Japan, 10.2355/tetsutohagane.TETSU-2015-004, 101, 8, 422-425, 2015.01, Dispersion behavior of intragranular NbC precipitates them in Nb added austenitic stainless steel were investigated via nanoscopic characterization, FIB-SEM slice-sectioning tomography, energy-dispersive X-ray spectrometry (EDS), selected area electron diffraction pattern (SAEDP) and transmission electron microscopy (TEM). The heterogeneous dispersion of fine intragranular NbC precipitates were visualized, and in particular, it was found that they were on the {111} slip plane and interacted with <110> dislocations..
51. Masahiro Shigeta, Tomoko Endo, Yui Kondo, Mitsugu Engo, Susumu Okada, Kenji Kaneko, Naotoshi Nakashima, Latex Polymer/Super Growth-Single-Walled Carbon Nanotube Composites with High Electroconductivity Fabricated by Wet Processing, BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN, 10.1246/bcsj.20140248, 87, 12, 1343-1348, 2014.12.
52. Shuhei Kobayashi, Kenji Kaneko, Kazuhiro Yamada, Takeshi Nishiyama, Masao Kikuchi, Norihiro Kanno, Junichi Hamada, High-temperature in-situ TEM straining of the interaction with dislocations and particles for Cu-added ferritic stainless steel, Microscopy, 63, S1, i28-i29, 2014.11.
53. Takeshi Nishiyama, Kenji Kaneko, Kazuhiro Yamada, Ryo Teranishi, Takeharu Kato, Tsukasa Hirayama, Hiroshi Tobita, Teruo Izumi, Yu Shiohara, Three-dimensional characterization of BaHfO3 precipitates in GdBa2Cu3O7-y film using STEM tomography, Microscopy, 63, S1, i26-i27, 2014.11.
54. Ryo Teranishi, Takeshi Nishiyama, Kenji Kaneko, Process and microstructural characterization of Yttrium based High-Tc superconducting thin films, Journal of the Society of Inorganic Materials Japan, 21, 314-320, 2014.09.
55. Kazuki Misumi, Kenji Kaneko, Takeshi Nishiyama, Takuya Maeda, Kazuhiro Yamada, Ken Ichi Ikeda, Masao Kikuchi, Ken Takata, Makoto Saga, Kohsaku Ushioda, Three-dimensional characterization of interaction between β″ precipitate and dislocation in Al-Mg-Si alloy, Journal of Alloys and Compounds, 10.1016/j.jallcom.2014.02.059, 600, 29-33, 2014.07, Interaction between precipitates and dislocations is the most important factor governing mechanical properties of precipitation-hardening alloys. Thus large numbers of microstructural characterizations have been implemented to analyze this interaction by measuring critical angles and precipitate intervals. To date, these investigations have been performed using two-dimensional conventional transmission electron microscopy. In this study, a combination of transmission electron microscopy and computed tomography, three-dimensional electron tomography, was applied on balanced Al-Mg-Si alloy to measure critical angles and precipitate intervals and obtained 121 and 60 nm for β″ precipitates, respectively. The yield stress of precipitates measured by assigning these values, 150 MPa, was applicable to that measured from tensile test, 196 MPa..
56. Takeshi Yatabe, Mitsuhiro Kikkawa, Takahiro Matsumoto, Hidetaka Nakai, Kenji Kaneko, Seiji Ogo, A model for the water-oxidation and recovery systems of the oxygen-evolving complex, Dalton Transactions, 10.1039/c3dt52846d, 43, 8, 3063-3071, 2014.02, We propose a model for the water-oxidation and recovery systems of the oxygen-evolving complex (OEC) of the photosystem II (PSII) enzyme. The whole system is constructed from two catalytic cycles, conducted as a tandem reaction: (i) a water-oxidation loop uses cerium(iv) ammonium nitrate as an oxidant to activate a dimanganese complex for water-oxidation and thereby liberate a molecule of O2 and (ii) a recovery loop begins with photoinhibition of the dimanganese complex but then uses O2 to reactivate the manganese centre. The net result is a catalytic water-oxidation catalyst that can use self-generated O2 for recovery..
57. Masahiro Shigeta, Tomoko Endo, Yui Kondo, Mitsugu Uejima, Susumu Okada, Kenji Kaneko, Naotoshi Nakashima, Latex polymer/super growth-single-walled carbon nanotube composites with high electroconductivity fabricated by wet processing, Bulletin of the Chemical Society of Japan, 10.1246/bcsj.20140248, 87, 12, 1343-1348, 2014.01, Acrylonitrile-butadiene rubbers (NBR) have been widely used in many industrial applications due to their very low cost and high performance. In this study, we focus on the fabrication of NBR/carbon nanotube (CNT) composites using surfactant dispersed super-growth SWNTs (SG-SWNTs) as the nanocarbon, and multi-walled carbon nanotubes for comparison. We found that the prepared NBR (15 wt %)/SG-SWNT composite showed a 10 S cm-1 conductance, which was much higher than that of the NBR (15 wt %)/MWNT composite. Such a high value would be due to the good dispersion of the/SG-SWNTs in the rubber matrix..
58. Kenji Kaneko, Yoshio Sakka, Yoshizumi Ishikawa, TEM characterization of nanocomposite materials, Transmission Electron Microscopy Characterization of Nanomaterials, 10.1007/978-3-642-38934-4_8, 333-373, 2014.01, In this chapter, we describe the introduction and application of 2-dimensional (2D) and 3-dimensional (3D) characterization by transmission electron microscopy (TEM) of two types of nanocomposite materials, ceramic matrix nanocomposites (CMNC), and polymer matrix nanocomposites (PMNCs), in particular. For the case of CMNC, structural and morphological characterizations of matrix and nanostructure phases were carried out, and for the case of PMNC, dispersion and distribution of nanoparticles as well as interparticle distances between them were investigated..
59. Tatsuya Fukunaga, Kenji Kaneko, Rika Kawano, Kakeru Ueda, Kazuhiro Yamada, Nobuo Nakada, Masao Kikuchi, Jonathan Simon Barnard, Paul Anthony Midgley, Formation of intergranular M23C6 in sensitized type-347 stainless steel, ISIJ International, 10.2355/isijinternational.54.148, 54, 1, 148-152, 2014.01, Formation of intergranular M23C6 carbides and thereafter Cr-depletion zones in commercially available type-347 stainless steels were observed by optical microscopy, conventional transmission electron microscopy and analytical transmission electron microscopy. At the early stage of sensitization, only NbC carbides were observed both intragranularly and intergranularly. At the later stage, formation of intergranular M 23C6 carbides and intergranular corrosion were found. A model is proposed to describe the formation kinetics of intergranular precipitation of NbC and of M23C6, as well as Cr-depletion zones, thermodynamically. Evolution mechanisms of intergranular precipitates were found in the order of 1) the formation of intergranular NbC, 2) the coarsening of NbC, 3) the formation of M23C6, then 4) the coarsening of M23C6 and formation of Cr-depletion zones..
60. Takashi Gondo, Kenji Kaneko, Takeshi Nishiyama, Kazuhiro Yamada, Zineb Saghi, Jonathan S. Barnard, Paul A. Midgley, Microstructural analysis of Au/TiO2-SBA-15 nanocomposite, Microscopy and Microanalysis, 10.1017/S1431927614000841, 20, 4, 1001-1007, 2014.01, Properties of gold nanoparticles (AuNPs) are very different from bulk gold, in particular, highly dispersed AuNPs exhibit high catalytic activities on metal oxide supports. Catalytic activities of AuNPs are strongly dependent on: (i) size and morphology; (ii) synthesis methods; (iii) nature of the support; (iv) interaction between AuNPs and the support; and (v) oxidation state of AuNPs in the synthesized catalysts. A goal is to maintain the size and to prohibit aggregation of AuNPs, since aggregations deteriorate catalytic activities. Some strong interactions are therefore required between AuNPs and their supports to prevent the movement of AuNPs. SBA-15 is a promising material for the support of AuNPs since it has ordered two-dimensional hexagonal pore channels, uniform pore size ranging from 5 to 30 nm, narrow pore size distribution, thick amorphous walls ranging from 3 to 6 nm, and high surface area. In this study, SBA-15, TiO2-SBA-15 and TiO2-SBA-15-AuNP nanocomposites were synthesized by the sol-gel method and microstructural characterizations were carried out by both X-ray diffraction analysis and electron microscopy..
61. T. Nishiyama, Kenji Kaneko, K. Yamada, Ryo Teranishi, T. Kato, T. Hirayama, T. Izumi, Y. Shiohara, Microstructural characterization of TFA-MOD processed Y1-xGdxBa2Cu3O7-y with BaZrO3, Micron, 10.1016/j.micron.2013.06.010, 52-53, 1-7, 2013.09, Y1-xGdxBa2Cu3O7-y with BaZrO3 film was fabricated on CeO2 buffered LaMnO3/ion beam assisted deposition-MgO/Gd2Zr2O7/Hastelloy C276TM substrates by the metal organic deposition process using trifluoroacetates. Both microstructural and analytical characterizations were performed by transmission electron microscopy with selected area electron diffraction method and energy dispersive X-ray spectroscopy. The thickness of Y1-xGdxBa2Cu3O7-y with BaZrO3 film was found approximately 700nm and the film was composed of c-axis oriented Y1-xGdxBa2Cu3O7-y grains. Several types of particles, (Y,Gd)2Cu2O5, CuO and BaZrO3, were formed within the Y1-xGdxBa2Cu3O7-y film, whose sizes were about 100-200nm for (Y,Gd)2Cu2O5 and CuO particles, and about 10-20nm for BaZrO3 particles, respectively. In the Y1-xGdxBa2Cu3O7-y film, (Y,Gd)2Cu2O5 and CuO particles were dispersed heterogeneously, whereas BaZrO3 nanoparticles were found dispersed homogeneously with random orientation. In addition, electron tomographic observation was carried out to attain the three-dimensional information of polyhedral BaZrO3 nanoparticles..
62. Razavi Khosroshahi Hadi, X. Liu, NAKASHIMA Kunihiko, Noritaka Saito, Kenji Kaneko, Effect of nano-sized particles on the mechanical properties of Y2O3, Materials Science Forum, 750, 44-47, 2013.08.
63. Takeshi Nishiyama, Ryo Teranishi, Kenji Kaneko, Takeharu Kato, Teruo Izumi, Yu Shiohara, Effect of nano-sized particles on the mechanical properties of Y2O3, Materials Science Forum, 750, 48-51, 2013.08, Three-dimensional characterization of BaZrO3 precipitates in Y1-xGdxBa2Cu3O7-y prepared by TFA-MOD using STEM-tomography
Yamada, K., Kato, T., Izumi, T., Shiohara, Y.
2013
Materials Science Forum 750 , pp. 48-51.
64. Kazuhiro Yamada, Kenji Kaneko, Yuki Yoshida, Takeshi Nishiyama, Ryo Teranishi, Koji Suzuki, Motoji Ito, Osuke Miura, Ryusuke Kita, Influences of calcination temperature on growth and superconducting properties of GdBa2Cu3O7-δ films fabricated by fluorine-free metal organic deposition method, Micron, 10.1016/j.micron.2013.04.004, 50, 44-50, 2013.07, GdBa2Cu3O7-δ is one of the best candidates for the superconducting coated conductors because it has high critical temperature and high critical current density under high magnetic fields. In this study, superconducting GdBa2Cu3O7-δ films were fabricated by fluorine-free metal organic deposition method via two different calcination temperatures, 723K and 873K, to examine the influence of calcination temperature on film growth and superconducting characteristics. Critical temperatures and critical current densities of the sample calcined at 873K were superior to the sample calcined at 723K. In the case of the sample calcined at 723K, the mixture of amorphous and crystalline phases was observed, and that of a- and c-axis oriented grains after the crystallization. In the case of the sample calcined at 873K, the randomly oriented crystalline phases were observed, and the mixture of c-axis oriented grains and (Gd, Al)2BaO4 phase after the crystallization. These microstructural changes caused the differences in superconducting characteristics..
65. Tsuyohiko Fujigaya, Minoru Okamoto, Kazuya Matsumoto, Kenji Kaneko, Naotoshi Nakashima, Interfacial engineering of platinum catalysts for fuel cells
Methanol oxidation is dramatically improved by polymer coating on a platinum catalyst, ChemCatChem, 10.1002/cctc.201300157, 5, 7, 1701-1704, 2013.07, All coated up: Platinum nanoparticles loaded on multiwalled carbon nanotubes (MWNTs) are coated with pyridine-containing polybenzimidazole (PyPBI). Interestingly, although a slight decrease in the accessibility of methanol is observed after coating, the methanol oxidation activity of Pt dramatically improves after coating with PyPBI..
66. K. Konya, K. Ootaguro, T. Nishiyama, Ryo Teranishi, Takanobu Kiss, K. Yamada, Kenji Kaneko, M. Yoshizumi, T. Izumi, Effect of holding temperature on microstructures and Jc properties of YBa2Cu3O7-X films fabricated by TFA-MOD method, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2013.04.067, 494, 144-147, 2013.05, In this study, we investigated the correlation between microstructures and critical current density (Jc) of YBa2Cu3O 7-X (YBCO) films with BaZrO3 (BZO) pinning centers by introducing holding temperature during the crystallization process. Smaller BZO particles and higher in-field Jc were found in the YBCO film with holding temperature than the one without. As a result, films with improved microstructures were successfully fabricated by implementation of additional process, holding temperature, and highly in-field Jc were obtained by introducing smaller BZO particles as artificial pinning centers..
67. Masayuki Shibata, Satoshi Tanaka, Tomohiro Ikeda, Seiji Shinkai, Kenji Kaneko, Soichiro Ogi, Masayuki Takeuchi, Stimuli-responsive folding and unfolding of a polymer bearing multiple cerium(IV) bis(porphyrinate) joints
Mechano-imitation of the action of a folding ruler, Angewandte Chemie - International Edition, 10.1002/anie.201205584, 52, 1, 397-400, 2013.01, A pivotal guest role: A new porphyrin polymer, poly(PorZn·DD) (see picture, pink/purple), composed of a porphyrinatozinc and a porphyrin double-decker complex as a repeating unit was synthesized. In poly(PorZn·DD), porphyrinatozinc complexes recognize a divalent amine (tan/red) to induce an intramolecular pivoting motion through the rotation of porphyrin double-decker complexes and the polymer undergoes shortening and compaction..
68. T. Watanabe, T. Kamata, T. Maebatake, Ryo Teranishi, Takanobu Kiss, K. Yamada, Kenji Kaneko, M. Yoshizumi, T. Izumi, Study of factors in joint resistance for GdBCO coated conductors, Physics Procedia, 10.1016/j.phpro.2013.04.078, 45, 165-168, 2013.01, Joint techniques are important to manufacture long superconducting tapes. It has been reported that GdBa2Cu3Oy (GdBCO) coated conductors have higher critical current and critical temperature than YBCO. However, it was reported that the joint resistance of GdBCO was found higher than that of YBCO. In this paper, the elemental distribution maps were investigated to examine the cause of joint resistance. Electron microscopy analysis of GdBCO showed the reduction of oxygen in GdBCO layer. This oxygen reduction may cause degradation of superconducting properties and increase of Ag-GdBCO interfacial resistance, which may have led higher joint resistance in Ag/GdBCO..
69. Hadi Razavi Khosroshahi, Xin Liu, Noritaka Saito, Kunihiko Nakashima, Kenji Kaneko, Effect of nano-sized particles on the mechanical properties of Y2O3, 8th International Forum on Advanced Materials Science and Technology, IFAMST 2012 Advanced Materials Science and Technology, 10.4028/www.scientific.net/MSF.750.44, 750, 44-47, 2013.01, Two types of TiO2/Y2O3 and ZrO2/Y2O3 composites were fabricated for enhancing the mechanical properties of Y2O3 ceramic. Results showed that ZrO2/Y2O3 composite dramatically increased the strength and toughness as 417 MPa and 4.4 MPa.m1/2, respectively..
70. T. Nishiyama, K. Yamada, Ryo Teranishi, Kenji Kaneko, T. Kato, T. Izumi, Y. Shiohara, Three-dimensional characterization of BaZrO3 precipitates in Y1-xGdxBa2Cu3O7-y prepared by TFA-MOD using STEM-tomography, 8th International Forum on Advanced Materials Science and Technology, IFAMST 2012 Advanced Materials Science and Technology, 10.4028/www.scientific.net/MSF.750.48, 750, 48-51, 2013.01, Y1-xGdxBa2Cu3O7-y film with BaZrO3 was fabricated on CeO2 buffered LaMnO3/ion beam assisted deposition MgO/Gd2Zr2O7/Hastelloy C276TM substrates by the trifluoroacetates metal organic deposition process, whose microstructural and elemental analyses were performed by transmission electron microscopy. Y1-xGdxBa2Cu3O7-y film with the thickness about 700 nm was found composed of c-axis oriented grains and large numbers of randomly oriented precipitates, such as (Y,Gd)2Cu2O5, CuO and BaZrO3. (Y,Gd)2Cu2O5 and CuO precipitates were heterogeneously dispersed in the Y1-xGdxBa2Cu3O7-y matrix with their sizes ranging between 100 and 200 nm, and BaZrO3 precipitates were uniformly dispersed with their sizes ranging between 10 and 20 nm. Electron tomography with elemental information was performed further to reveal the threedimensional information of BaZrO3 precipitates..
71. H. Suzuki, R. Kita, K. Ohba, O. Miura, Y. Ohtsu, K. Yamada, Kenji Kaneko, Effects of Zr Addition on the Superconducting Properties and Microstructure of MOD-GdBa
2
Cu
3
O
y
Films Fabricated Using Fluorine-free Coating Solutions, 26th International Symposium on Superconductivity, ISS 2013 Physics Procedia, 10.1016/j.phpro.2014.09.035, 58, 162-165, 2013.01, We have fabricated undoped and Zr-doped GdBa
2
Cu
3
O
y
(GdBCO) films on LaAlO
3
single-crystal substrates by metal-organic deposition (MOD) using 2-ethylhexanate (2-EH) solutions, which contain no fluorine. Zr-doped GdBCO films showed improved J
c
-B properties compared to the pure films. The J
c
and α values of 1-mol%-Zr-doped GdBCO films were 1.58 MA/cm
2
and 0.53, respectively, while those of the pure films were 1.90 MA/cm
2
and 0.68, respectively..
72. J. S. Barnard, J. H. Sharp, Satoshi Hata, Masatoshi Mitsuhara, Kenji Kaneko, K. Higashida, 3-dimensional imaging of dislocation microstructures by electron beams, 2011 MRS Fall Meeting Three-Dimensional Tomography of Materials, 10.1557/opl.2012.430, 1421, 30-40, 2012.12, We review the progress in the electron tomography of dislocation microstructures in the transmission electron microscope (TEM). Dislocation contrast is visible both in conventional TEM and scanning TEM (STEM) modes and, despite the complicated intensity variations, dislocation contrast can be isolated using computational filtering techniques prior to reconstruction. We find that STEM annular dark-field (STEM-ADF) imaging offers significant advantages in terms of dislocation contrast and background artifacts. We present several examples, both in semiconducting and metallic systems, illustrating the properties of 3D dislocations. We present the high-angle triple-axis (HATA) specimen holder where the diffraction condition can be chosen at will and dislocation tomograms of multiple reflections can be combined. 3D dislocations are analyzed in terms of dislocation density and dislocation nodal structures. Several avenues of study are suggested that may exploit the 3D dislocation data..
73. T. Yoshimoto, Y. Fujii, Ryo Teranishi, K. Kurumi, K. Yoshida, Y. Yoshida, Y. Ichino, T. Nishiyama, Shinji Munetoh, Kenji Kaneko, A novel approach for preparing Fe(Te xS y) superconducting films
Solid phase epitaxial growth from amorphous precursors, Superconductor Science and Technology, 10.1088/0953-2048/25/10/105013, 25, 10, 2012.10, Fe(Te xS y) films were fabricated on (100) SrTiO 3 substrates from Fe(Te 0.65S 0.16) amorphous precursors by a solid phase epitaxial growth process under various background atmospheric conditions. Structural analysis by x-ray diffraction showed strong peaks corresponding to Fe(Te xS y) phases, when the amorphous precursors were heated with Fe(Te 0.8S 0.2) sintered pellets. The crystallinity of the films deteriorated at longer periods of heating but the compositional shifts were found to have decreased. Consequently, the critical temperature, T Czero, of the Fe(Te xS y) film with minimum compositional shift was found to be 9.0K and critical current density, J C, of the film was about 1.4×10 4Acm 2..
74. Hadi Razavi Khosroshahi, Hiroyuki Ikeda, Kazuhiro Yamada, Noritaka Saito, Kenji Kaneko, Koichi Hayashi, Kunihiko Nakashima, Effect of cation doping on mechanical properties of yttria prepared by an optimized two-step sintering process, Journal of the American Ceramic Society, 10.1111/j.1551-2916.2012.05379.x, 95, 10, 3263-3269, 2012.10, Undoped Y 2O 3 and Y 2O 3 doped with either Si 4+, Er 3+, Yb 3+, Al 3+ or Ti 4+ were fabricated by a two-step sintering method. The concentration of each dopant cation (Si 4+, Er 3+, Yb 3+, Al 3+, and Ti 4+) was adjusted so that the dopant:yttria molar ratio was 0.01 and the mechanical properties and the microstructures of each were characterized. The Vickers hardness and the bending strength of cation-doped Y 2O 3 increased in the order Si 4+, Er 3+, Yb 3+, Al 3+, and Ti 4+ paralleling increases in the relative density. Ti-doped-Y 2O 3 had the highest density and the highest strength. Transmission electron microscopy analysis revealed that Ti segregated to the grain boundaries of Y 2O 3. The two-step sintering method was optimized to enhance the mechanical properties of Y 2O 3. As a consequence, Ti-doped Y 2O 3 with the Ti 4+:yttria molar ratio of 0.01 sintered at the optimized heating schedule was found to have a Vickers hardness and three-point bending strength as high as 874 Hv and 307.0 MPa, respectively..
75. T. Yanagimoto, Y. T. Yu, Kenji Kaneko, Microstructure and CO gas sensing property of Au/SnO 2 core-shell structure nanoparticles synthesized by precipitation method and microwave-assisted hydrothermal synthesis method, Sensors and Actuators, B: Chemical, 10.1016/j.snb.2011.11.047, 166-167, 31-35, 2012.05, Au/SnO 2 core-shell structure NPs were prepared by a precipitation method and a microwave hydrothermal synthesis method, and their CO responses were measured by a high resistance meter. It was found that the CO response of the sample prepared by the precipitation method was extremely low, 0.18, with comparison to the one by the hydrothermal synthesis method, 0.965. Microstructures achieved by two-dimensional TEM characterization showed that both samples maintained the similar core-shell structures with their sizes ranging between 30 and 50 nm, as the core consists of Au NP and the shell consists of SnO 2 NPs. The average grain sizes of SnO 2 NPs of precipitation method and hydrothermal synthesis method were measured as 5.2 nm and 8.3 nm, respectively. The thickness and the porosity variation of SnO 2-shell layers were characterized further by three-dimensional electron tomography, and correlated with the sensing properties. It was found that the porosity within SnO 2-shell layers prepared by the precipitation method was lower than the one prepared by the hydrothermal synthesis method. Since Au NP could act as the catalyst for CO oxidation reaction, high porosity within SnO 2-shell layers would have lead the accessibilities of Au NP to the CO gas molecules and resulted high CO responses..
76. Ryusuke Kita, Keita Kuroda, Teppei Kato, O. Miura, K. Yamada, K. Kaneko, Effects of TFA addition on the growth of sintered YBa2Cu3Oy superconductors, Physics Procedia, 10.1016/j.phpro.2012.03.426, 27, (2012) 124 – 127, 2012.04.
77. Keita Kuroiwa, Masaki Yoshida, Shigeyuki Masaoka, Kenji Kaneko, Ken Sakai, Nobuo Kimizuka, Self-assembly of tubular microstructures from mixed-valence metal complexes and their reversible transformation by external stimuli, Angewandte Chemie - International Edition, 10.1002/anie.201105080, 51, 3, 656-659, 2012.01, Mix and shake: Lipid packaged dinuclear ruthenium(II,III) complexes of class III mixed-valence state produce a reversible hypochromic effect upon external physical stimuli, such as shaking, due to the arrangement of transition dipole moments. The effect is accompanied by tubular-to-ribbon structural changes (see scheme)..
78. Naoko Sato, Yoshitaka Adachi, Hiroyuki Kawata, Kenji Kaneko, Topological approach to ferrite/martensite dual-phase microstructures, ISIJ International, 10.2355/isijinternational.52.1362, 52, 7, 1362-1365, 2012.01, In this study, three different microstructures of dual-phase (DP) steel obtained by varying the intercritical annealing temperature were observed three dimensionally by a serial-sectioning method and their metrics and topological properties were quantified. The results demonstrated that martensite in DP steels has various morphologies such as layers, particles, holes, and voids. The fraction of these characteristic morphologies was examined as a function of the intercritical annealing temperature..
79. Takahiro Kaseyama, Rie Wakabayashi, Seiji Shinkai, Kenji Kaneko, Masayuki Takeuchi, Alternating arrays of different conjugated polymers utilizing a synthetic cross-linker, Chemistry - A European Journal, 10.1002/chem.201002675, 17, 6, 1793-1797, 2011.12, Exploring an approach to control the nanostructures of pconjugated polymers has been an important research target in materials science, which has led to the creation of various functional materials with optimized p-electronic properties.In particular, nanostructures of conjugated oligomer/polymer blends have received growing interest in their applications, which include electronic devices such as fieldeffect transistors, light-emitting diodes, photovoltaic cells.Several methods for controlling dimensionality, nanostructure, and morphology have been achieved through chemical and physical techniques that utilize microphase separation, layer-by-layer method, and so forth.Supramolecular approaches also have been applied for the alignment and organization of conjugated oligomers and polymers in a noncovalent manner, use of host matrix, liquid-crystalline phase, airwater interface, and so forth.From a supramolecular point of view, we recently proposed a new approach toward the alignment of conjugated polymers inspired by actin filament bundling proteins. A supramolecular cross-linking molecule ("aligner"), possessing conjugated polymer binding sites, bundles and aligns them in a noncovalent fashion. The concepts we have reported complement the existing techniques for supramolecular and macromolecular assembly. Introducing interactive sites for conjugated polymers at the spacial position of the aligner molecules allows control over the dimensions, morphologies, and interpolymer spacings.This approach basically permits the construction of alternating arrays of different conjugated polymers, which depends upon the design of an aligner molecule displaying affinities toward such polymers..
80. Takatoshi Yoshimoto, Kenta Yuki, Ryo Teranishi, Shinji Munetoh, Kenji Kaneko, Influence of Ar background gas pressure on composition and crystal orientation in PLD-Fe(Se1-xTex) thin films, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2011.09.009, 471, 23-24, 1616-1620, 2011.12, Fe(Se1-xTex) thin films on (1 0 0) SrTiO3 were fabricated by a pulsed laser deposition method, and their crystal orientation, compositional shifts and superconducting properties were characterized by X-ray diffraction, scanning electron microscope combined with energy dispersive X-ray spectroscopy, etc. Compositional shift is one of the major problems during the fabrication of Fe(Se1-xTe x) films due to its containing high volatile elements such as Se and Te. The compositional shifts were found dependent on the Ar background gas pressure (PAr), which was suppressed by the increase of P Ar. In addition, it was revealed that the temperature window for the crystallization of the films was shifted to higher temperature region and wider temperature range with the increase of PAr..
81. T. Maebatake, Y. Ichinose, K. Yamada, N. Mori, Ryo Teranishi, Masayoshi Inoue, Takanobu Kiss, M. Yoshizumi, T. Izumi, Kenji Kaneko, Shinji Munetoh, Masashi Mukaida, Joint properties of REBCO coated conductors, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2011.05.106, 471, 21-22, 987-989, 2011.11, We investigated joint properties of REBCO (REBa2Cu 3O7-X, RE = rare earth element) coated conductors using a diffusion joint process. Two pieces of the coated conductor tapes with stabilizing silver layer on REBCO were overlapped in a face to face manner, which were pressurized and heat-treated at about 623-673 K in oxygen atmosphere. The joint resistance for YBCO tape was about 6.5 nΩ cm 2 at 77 K, on the other hand, that for GdBCO tape was about 37 nΩ cm2 which was higher than YBCO. From the results of both cross-sectional transmission electron microscope (TEM) and energy dispersive X-ray spectrometry (EDS) analysis, diffusion of Gd-element into Ag layer was observed for the joined sample of GdBCO tape, it is suggested to be a cause of higher joint resistance for GdBCO tape..
82. R. Kita, K. Suzuki, T. Takeuchi, T. Iwasa, O. Miura, Y. Ichino, T. Yoshimura, Y. Yoshida, K. Yamada, Kenji Kaneko, A. Ichinose, Stable barium compounds in YBa2Cu3Oy superconductors, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2011.05.074, 471, 21-22, 859-862, 2011.11, The stability of various amounts of Ba3Cu3In 4O12 (334) or BaTbO3 (BTO) in a sintered YBa2Cu3Oy (YBCO) matrix was examined. Samples with added 334 or BTO exhibited critical temperatures (Tc) above 90 K for up to 20 vol.% addition and improved critical current densities (J c) under a magnetic field. X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) analysis indicated that 334 and BTO did not react with the YBCO matrix under the sintering conditions used. The normalized Jc under a magnetic field of 1 T reached a maximum at 14 vol.% of 334 addition and 20 vol.% BTO addition. YBCO thin films with added BTO showed a gradual decrease in the Tc with increasing BTO content. YBCO films with added 334 showed a constant Tc of 87 K up to a 334 content of 4 vol.%..
83. Kenji Kaneko, Tatsuya Fukunaga, Kazuhiro Yamada, Nobuo Nakada, Masao Kikuchi, Zineb Saghi, Jon S. Barnard, Paul A. Midgley, Formation of M23C6-type precipitates and chromium-depleted zones in austenite stainless steel, Scripta Materialia, 10.1016/j.scriptamat.2011.06.010, 65, 6, 509-512, 2011.09, Formation of M23C6 carbides and chromium-depleted zones in commercially available type 304L stainless steel were investigated by in situ transmission electron microscopy and analytical transmission electron microscopy. It was found that each individual small M23C6 carbide starts to grow with a clear orientation relationship with the matrix, and film-like carbide was subsequently observed at the interfaces with asymmetric Cr-depleted zones. From these experimental results, a model describing the precipitation of M23C6 and the formation of the Cr-depleted zone was proposed..
84. Satoshi Hata, H. Miyazaki, S. Miyazaki, Masatoshi Mitsuhara, Masaki Tanaka, Kenji Kaneko, K. Higashida, K. Ikeda, Hideharu Nakashima, Syo Matsumura, J. S. Barnard, J. H. Sharp, P. A. Midgley, High-angle triple-axis specimen holder for three-dimensional diffraction contrast imaging in transmission electron microscopy, Ultramicroscopy, 10.1016/j.ultramic.2011.03.021, 111, 8, 1168-1175, 2011.07, Electron tomography requires a wide angular range of specimen-tilt for a reliable three-dimensional (3D) reconstruction. Although specimen holders are commercially available for tomography, they have several limitations, including tilting capability in only one or two axes at most, e.g. tilt-rotate. For amorphous specimens, the image contrast depends on mass and thickness only and the single-tilt holder is adequate for most tomographic image acquisitions. On the other hand, for crystalline materials where image contrast is strongly dependent on diffraction conditions, current commercially available tomography holders are inadequate, because they lack tilt capability in all three orthogonal axes needed to maintain a constant diffraction condition over the whole tilt range. We have developed a high-angle triple-axis (HATA) tomography specimen holder capable of high-angle tilting for the primary horizontal axis with tilting capability in the other (orthogonal) horizontal and vertical axes. This allows the user to trim the specimen tilt to obtain the desired diffraction condition over the whole tilt range of the tomography series. To demonstrate its capabilities, we have used this triple-axis tomography holder with a dual-axis tilt series (the specimen was rotated by 90° ex-situ between series) to obtain tomographic reconstructions of dislocation arrangements in plastically deformed austenitic steel foils..
85. J. Zhang, T. Naka, S. Ohara, Kenji Kaneko, T. Trevethan, A. Shluger, T. Adschiri, Surface ligand assisted valence change in ceria nanocrystals, Physical Review B - Condensed Matter and Materials Physics, 10.1103/PhysRevB.84.045411, 84, 4, 2011.07, In this report, we used x-ray absorption, electron energy-loss, and magnetic analyses to demonstrate the effect of modification of ceria (CeO 2-δ) nanocrystals with a particle size D= 3.5-14 nm by oleic acid surface ligands. We observe a shift of the electronic state of the cerium ions from tetra to trivalent state as the surface density of the ligand molecules is increased. The valence state of cerium in the nanocrystal is strongly correlated with the number of ligand molecules bound to the surface of the ceria nanocrystals. One oxygen vacancy is stabilized by 5-6 ligand molecules bound on a CeO2-δ nanocrystal..
86. Takao Noguchi, Chie Chikara, Keita Kuroiwa, Kenji Kaneko, Nobuo Kimizuka, Controlled morphology and photoreduction characteristics of polyoxometalate(POM)/lipid complexes and the effect of hydrogen bonding at molecular interfaces, Chemical Communications, 10.1039/c1cc10231a, 47, 22, 6455-6457, 2011.06, Supramolecular complexes consisting of anionic polyoxometalate (POM) and chiral, cationic lipids are newly developed. They give nanofibers, helical ribbons, and nanotapes in organic media depending on the chemical structure of lipid molecules. Lipid ammonium groups exert significant influence on their photoreduction characteristics..
87. Shoji Sadayama, Hiromi Sekiguchi, Alexander Bright, Naohisa Suzuki, Kazuhiro Yamada, Kenji Kaneko, High-resolution three-dimensional scanning transmission electron microscopy characterization of oxide-nitride-oxide layer interfaces in Si-based semiconductors using computed tomography, Microscopy (Oxford, England), 10.1093/jmicro/dfr029, 60, 3, 243-251, 2011.06, Oxide-nitride-oxide (ONO) layer structures are widely used for charge storage in flash memory devices. The ONO layer interfaces should be as flat as possible, so measurement of the nanoscale roughness of those interfaces is needed. In this study, quantification of an ONO film from a commercially available flash memory device was carried out with a pillar-shaped specimen using scanning transmission electron microscopy (STEM) and computed tomography. The ONO area contained only low Z-and low STEM-contrast materials, which makes high-quality reconstruction difficult. The optimum three-dimensional reconstruction was achieved with an STEM annular dark-field detector inner collection angle of 32 mrad, a sample tilt range from-78° to +78° and 25 iterations for the simultaneous iterative reconstruction technique..
88. S. Sadayama, H. Sekiguchi, A. Bright, N. Suzuki, K. Yamada and K. Kaneko, High resolution three-dimensional STEM characterization of ONO layer interfaces in Si-based semiconductors using Computed Tomography, Journal of Electron Microscopy, 60, 3, 243-251, (2011), 2011.03.
89. Jing Zhang, Hitoshi Kumagai, Kae Yamamura, Satoshi Ohara, Seiichi Takami, Akira Morikawa, Hirofumi Shinjoh, Kenji Kaneko, Tadafumi Adschiri, Akihiko Suda, Extra-low-temperature oxygen storage capacity of CeO2 nanocrystals with cubic facets, Nano Letters, 10.1021/nl102738n, 11, 2, 361-364, 2011.02, Herein we demonstrate the extra-low-temperature oxygen storage capacity (OSC) of cerium oxide nanocrystals with cubic (100) facets. A considerable OSC occurs at 150 °C without active species loading. This temperature is 250 °C lower than that of irregularly shaped cerium oxide. This result indicates that cubic (100) facets of cerium oxide have the characteristics to be a superior low-temperature catalyst..
90. K. Sugikawa, K. Kaneko, K. Sada, S. Shinkai, A molecular template designed by the modification of a helix-forming β-1,3-glucan polysaccharide to fabricate one-dimensional nanostructures, Langmuir, 10.1021/la101335a, 26, 24, 19100-19105 , (2010), 2011.01.
91. Dakrong Pissuwan, Keisuke Nose, Ryohsuke Kurihara, Kenji Kaneko, Yoshiro Tahara, Noriho Kamiya, Masahiro Goto, Yoshiki Katayama, Takuro Niidome, A solid-in-oil dispersion of gold nanorods can enhance transdermal protein delivery and skin vaccination, Small, 10.1002/smll.201001394, 7, 2, 215-220, 2011.01, A high-molecular-weight model protein, ovalbumin (OVA), can be delivered through the skin and induce an immune response in mice by a solid-in-oil dispersion of gold nanorods after irradiation with near-infrared light..
92. Kouta Sugikawa, Munenori Numata, Daiki Kinoshita, Kenji Kaneko, Kazuki Sada, Atsushi Asano, Shu Seki, Seiji Shinkai, Hierarchical polymer assemblies constructed by the mutual template effect of cationic polymer complex and anionic supramolecular nanofiber, Organic and Biomolecular Chemistry, 10.1039/c0ob00407c, 9, 1, 146-153, 2011.01, Creation of higher-ordered polymeric architectures composed of alternative assemblies of single-walled carbon nanotubes (SWNTs) and fibrous porphyrin J-aggregates can be easily achieved utilizing the cationic semi-artificial polysaccharide which can act not only as a tubular host for SWNTs but also as a one-dimensional template for porphyrin molecules. This new class of hierarchical polymer assembly is formed, for the first time, by the mutual template effect of two components, i.e., the cationic SWNT complexes and the anionic porphyrin supramolecular nanofibers. In the present system, the self-assembling behaviors of the SWNT complexes as well as the final properties of the SWNT nanoarchitectures are strongly affected by the packing mode of porphyrin molecules on the cationic semi-artificial polysaccharide. Furthermore, we have confirmed that the light energy captured by the porphyrin J-aggregates is effectively transferred to SWNTs..
93. Kenji Kaneko, Characterization of crystalline materials by electron tomography, Journal of the Vacuum Society of Japan, 10.3131/jvsj2.54.253, 54, 4, 253-255, 2011.01, Combination of transmission electron microscopy and computed tomography (TEM-CT) is a powerful technique to characterize three-dimensional nature of materials. In this paper, its principle and application are described in detail. In addition, as an example, TEM and TEM-CT was applied on TiN-Ag nanocomposite synthesized by dc arc-plasma method. Microstructures of TiN-Ag nanocomposite were carefully characterized by TEM, and nano-morphologies by TEM-CT. It was found that the surface of nanocrystalline TiN matrix was covered by finely dispersed Ag nanoparticles, and it was found that they were physically attached but not chemically bonded. From these experimental results, formation mechanisms are also predicted..
94. Tsuyohiko Fujigaya, Takeshi Uchinoumi, Kenji Kaneko, Naotoshi Nakashima, Design and synthesis of nitrogen-containing calcined polymer/carbon nanotube hybrids that act as a platinum-free oxygen reduction fuel cell catalyst, Chemical Communications, 10.1039/c1cc11303h, 47, 24, 6843-6845, 2011.01, The development of a platinum-free catalyst is one of the challenging issues for the global commercialization of fuel cell systems. Here we describe the design and synthesis of nitrogen-containing calcined polybenzimidazole/ carbon nanotube hybrids that act as an oxygen reduction catalyst..
95. Kouta Sugikawa, Kenji Kaneko, Kazuki Sada, Seiji Shinkai, A molecular template designed by the modification of a helix-forming β-1,3-glucan polysaccharide to fabricate one-dimensional nanostructures, Langmuir, 10.1021/la101335a, 26, 24, 19100-19105, 2010.12, We report the development of a new templating molecule designed by the modification of a helix-forming β-1,3-glucan polysaccharide to the cationic semiartificial one and its application to the fabrication of one-dimensional (1D) gold nanostructures by simple photoirradiation. Transmission electron microscopy observation showed that Au(III) ions are primarily reduced to gold nanoparticles self-assembling into the 1D array with the aid of the cationic β-1,3-glucan polysaccharide, which gradually fuse into the 1D gold nanostructure with the tapelike structure. The gold nanotape structure could not be created by neutral β-1,3-glucan polysaccharides or random coil synthetic cationic polymers. These findings consistently support the view that Au(III) ions are reduced by unmodified OH groups to gold nanoparticles under the photoirradiation, which are wrapped in the helical structure of the cationic β-1,3-glucan polysaccharide and eventually fuse into gold nanotapes. One may regard, therefore, that this cationic β-1,3-glucan polysaccharide can act as an "all-in-one" template playing three roles of reduction, 1D arrangement, and fusion of gold nanoparticles. In addition, we found an interesting phenomenon that the obtained gold nanotapes coated with cationic β-1,3-glucan polysaccharides show unique surface-enhanced Raman scattering for anionic porphyrines organized on the surface of gold nanotapes through the electrostatic interaction..
96. R. Kita, S. Nakamura, K. Sakimoto, T. Nakamura, O. Miura, K. Matsumoto, P. Mele, K. Yamada, Kenji Kaneko, A. Ichinose, Effects of indium doping on the superconducting properties of YBa 2Cu3Oy sintered compounds and thin films, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2010.05.073, 470, 20, 1198-1200, 2010.11, We investigated the effects of indium doping on the superconducting properties of YBCO sintered samples and thin films. In2O 3-doped YBCO and YBa2Cu3 xInxO y sintered samples showed a gradual decrease in the critical temperature (Tc) with increasing indium content; however, a T c value above 80 K was maintained even up to 30 vol.% addition and x = 0.4, respectively. Ba3Cu3In4O12 was detected by X-ray diffractometry and energy-dispersive X-ray spectroscopy as a reaction product for both sintered samples. The normalized Jc under a magnetic field of 0.1 T showed a maximum at x = 0.3. Indium-doped YBCO films prepared by pulsed laser deposition showed a similar dependence of T c on indium content as the sintered samples..
97. Zhenquan Tan, Hiroki Chihara, Chiyoe Koike, Hiroya Abe, Kenji Kaneko, Kazuyoshj Sato, Satoshi Ohara, Interstellar analogs from defective carbon nanostructures account for interstellar extinction, Astronomical Journal, 10.1088/0004-6256/140/5/1456, 140, 5, 1456-1461, 2010.11, Because interstellar dust is closely related to the evolution of matter in the galactic environment and many other astrophysical phenomena, the laboratory synthesis of interstellar dust analogs has received significant attention over the past decade. To simulate the ultraviolet (UV) interstellar extinction feature at 217.5 nm originating from carbonaceous interstellar dust, many reports focused on the UV absorption properties of laboratory-synthesized interstellar dust analogs. However, no general relation has been established between UV interstellar extinction and artificial interstellar dust analogs. Here, we show that defective carbon nanostructures prepared by high-energy collisions exhibit a UV absorption feature at 220 nm which we suggest accounts for the UV interstellar extinction at 217.5 nm. The morphology of some carbon nanostructures is similar to that of nanocarbons discovered in the Allende meteorite. The similarity between the absorption feature of the defective carbon nanostructures and UV interstellar extinction indicates a strong correlation between the defective carbon nanostructures and interstellar dust..
98. T. Nakamura, R. Kita, O. Miura, A. Ichinose, K. Yamada, Kenji Kaneko, Superconducting properties of Sm0.33Eu0.33Gd 0.33Ba2Cu3Oy films by metal-organic deposition using metal 2-ethylhexanates, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2010.05.086, 470, 20, 1249-1252, 2010.11, We have prepared Sm0.33Eu0.33Gd0.33Ba 2Cu3Oy (SEGBCO) films on LaAlO3 single-crystal substrates by metal-organic deposition using 2-ethylhexanate solutions which contain no fluorine. The SEGBCO film fired at 850 °C under a low oxygen partial pressure of 2 × 106 atm exhibited strong c-axis oriented X-ray diffraction peaks and weak a/b-axis oriented peaks of the SEGBCO phase, and had a granular surface. High resolution cross-sectional transmission electron microscope images indicated the epitaxial growth of the SEGBCO film on the substrate with overgrowth of a/b-axis oriented grains. The critical temperature and critical current density values of the SEGBCO film was 86.5 Kand 1.29 MA/cm2, respectively, at 77.3 K at the self-field..
99. T. Takaki, K. Kurosawa, N. Saito, H. Razavi, K. Kaneko, K. Nakashima and T. Hiraaki, Electrolytic synthesis of Al-doped ZnO nanopowders with low electrical resistivity, Journal of American Ceramics Society, 93, 10, 3088–3091, (2010), 2010.10.
100. Takeshi Takaki, Keiko Kurosawa, Hadi Razavi, Sohei Sukenaga, Noritaka Saito, Kenji Kaneko, Kunihiko Nakashima, Taisei Hiraakiy, Electrolytic synthesis of Al-doped ZnO nanopowders with low electrical resistivity, Journal of the American Ceramic Society, 10.1111/j.1551-2916.2010.04048.x, 93, 10, 3088-3091, 2010.10, Al-doped ZnO (AZO) nanopowders with different Al content were fabricated by a galvanostatic electrolytic method. The electrical resistivities were measured by a cell method, which reached its minimum (28 Ω.cm) at 0.93 at.% of Al with its grain size of ̃30 nm. Microstructures of powders were characterized by X-ray diffraction and transmission electron microscopy (TEM), which showed a decrease in grain size with the increase of Al content. In addition, the distributions of Al and the chemical bonding nature of Al atoms were examined by STEM-EDS and by X-ray photoelectron spectra, respectively, which suggested the substituational incorporation of Al atom into the ZnO lattice. Absorption properties were investigated for wavelength ranging from 250 to 2500 nm, which showed that the film coated with AZO nanopowders exhibited a rapid decrease in transmittance below 370 nm to ̃0% and beyond 1250 nm to ̃40% (at 2000 nm)..
101. Kenji Kaneko, Kenji Furuya, K. Yamada, S. Sadayama, J. S. Barnard, P. A. Midgley, T. Kato, T. Hirayama, M. Kiuchi, T. Matsushita, A. Ibi, Y. Yamada, T. Izumi, Y. Shiohara, Three-dimensional analysis of BaZrO3 pinning centers gives isotropic superconductivity in GdBa2 Cu3 O 7-δ, Journal of Applied Physics, 10.1063/1.3486213, 108, 6, 2010.09, BaZrO3 doped GdBa2 Cu3 O 7-δ superconductor was prepared by pulsed layer deposition using a KrF excimer laser, which showed isotropic characteristics of critical current density, JC, for magnetic-field orientations, ∼4.0× 109 A m-2 at 1.0 T. Microstructural and morphological characterization of resulting artificial pinning centers were conducted by transmission electron microscopy and electron tomography, which confirmed the presence of one-dimensional artificial pinning centers, BaZrO3 nanorods. Since there is noticeable anisotropy from GdBa2 Cu 3 O7-δ superconductor without doping BaZrO 3, the pinning observed for all magnetic-field orientations are due to the high density and high dispersion of these BaZrO3 nanorods with very wide angular distributions..
102. H. Razavi, K. Yamada, T. Katayama, N. Saito, K. Nakashma, K. Kaneko, Fabrication and Characterization of Mo-SiO2 Composite, Proceeding of the 2d International Symposium on Advanced Microscopy and Theoretical Calculations, 2, 248-249, 2010.06.
103. T. Takaki, K. Kurosawa, S. Sukenaga, N. Saito, H. Razavi, K. Kaneko, K. Nakashima, E. Okunishi and T. Hiraaki, Electrolytic synthesis of Al-doped ZnO powders with low electrical resistivity, Proceeding of the 2d International Symposium on Advanced Microscopy and Theoretical Calculations, 2, 266-267, 2010.06.
104. K. Kaneko, K. Furuya, K. Yamada, S. Sadayama, E. Okunishi, J. S. Barnard, P. A. Midgley, T. Kato, T. Hirayama, M. Kiuchi, T. Matsushita, Y. Yamada, T. Izumi and Y. Shiohara, 3D analysis of pinning centers in superconductive GdBa2Cu3O7-x, Proceeding of the 2d International Symposium on Advanced Microscopy and Theoretical Calculations, 2, 264-265, 2010.06.
105. Selective inclusion of anionic quantum dots in coordination network shells of nucleotides and lanthanide ions
R. Nishiyabu, C. Aimé, R. Gondo, K. Kaneko and N. Kimizuka
Chem. Comm. 46 (24) 4333-4335 (2010) , [URL].
106. Kenji Kaneko, K. Kitawaki, S. Sadayama, H. Razavi, J. C. Hernandez-Garrido, P. A. Midgley, H. Okuyama, M. Uda, Y. Sakka, Fabrication and characterization of TiN nanocomposite powders fabricated by DC arc-plasma method, Journal of Alloys and Compounds, 10.1016/j.jallcom.2009.12.017, 492, 1-2, 685-690, 2010.03, TiN nanocomposite powders with various morphologies were synthesized by DC arc-plasma method from Ti-Si ingot under N2-H2-Ar atmosphere. Microstructures of powders were characterized by powder X-ray diffraction method and transmission electron microscopy with compositional analysis, then morphologies by three-dimensional electron tomography. It was found that the powders were consisted of TiN nanoparticles covered by Ti5Si3 nanoparticles, which possibly suppressed the growth of facets and controlled the final morphologies of TiN-Ti5Si3 nanocomposite..
107. S. Sadamatsu, M. Tanaka, K. Higashida, K. Kaneko, M. Mitsuhara, S. Hata, M. Honda, Crack tip dislocations observed by combining scanning transmission electron microscopy and computed tomography, Advanced Materials Research , 89-91 , 473-478 , (2010), 2010.02.
108. Keiko Sasaki, K. Takatsugi, Kenji Kaneko, N. Kozai, T. Ohnuki, O. H. Tuovinen, Tsuyoshi Hirajima, Characterization of secondary arsenic-bearing precipitates formed in the bioleaching of enargite by Acidithiobacillus ferrooxidans, Hydrometallurgy, 10.1016/j.hydromet.2009.12.012, 104, 3-4, 424-431, 2010.01, The purpose of this study was to characterize secondary minerals that were formed in the bioleaching of enargite (Cu3AsS4) by Acidithiobacillus ferrooxidans. Two parallel cultures were used: one was adapted to arsenic in the growth medium and the other was wild-type. The progress of the solubilization of As in A. ferrooxidans cultures was stepwise and different from that observed in the non-adapted culture. In contrast, the bioleaching of Cu and Fe from enargite was not affected by prior adaptation of the culture. Minor presence of jarosite was observed by X-ray diffraction (XRD) in solid residues after the bioleaching, and no other peaks of secondary crystalline minerals were detected. The relative intensities of As 3d and Fe 2p to Cu 2p in X-ray photoelectron spectroscopy (XPS) for the solid residues were at maximum at 46 days after the bioleaching with As-adapted A. ferrooxidans. The results from the examination of solid residues with XPS, transmission electron microscopy with energy-dispersive microprobe (TEM-EDS) and XRD after 46 days of contact with As-adapted A. ferrooxidans showed the presence of metastable, amorphous ferric arsenate as an intermediate on the surface of enargite and minor amounts of jarosite. The amorphous ferric arsenate phase did not appear to have an adverse effect of the dissolution of Cu from enargite..
109. S. Sadamatsu, Masaki Tanaka, K. Higashida, Kenji Kaneko, Masatoshi Mitsuhara, Satoshi Hata, M. Honda, Crack tip dislocations observed by combining scanning transmission electron microscopy and computed tomography, 6th International Conference on Processing and Manufacturing of Advanced Materials - THERMEC'2009 THERMEC 2009 Supplement, 10.4028/www.scientific.net/AMR.89-91.473, 89-91, 473-478, 2010.01, Crack tip dislocations and dislocations introduced by three point-bending tests at high temperature are observed by combinating scanning transmission electron microscopy and computed tomography (STEM-CT). Commercially available P type (001) single crystal silicon wafers were employed. A series of STEM image was acquired from -60° to +60° in tilt range with 2° in tilt step. The diffraction vector was maintained close to g(hkl) = 220 during the acquisition by adjusting the [110] direction of the sample parallel to the tilt axis of the holder. Reconstructed images of dislocations revealed dislocation structures in three-dimension..
110. Ryuhei Nishiyabu, Carole Aimé, Ryosuke Gondo, Kenji Kaneko, Nobuo Kimizuka, Selective inclusion of anionic quantum dots in coordination network shells of nucleotides and lanthanide ions, Chemical Communications, 10.1039/c001012j, 46, 24, 4333-4335, 2010.01, Anionic quantum dots (QDs) are spontaneously enfolded by coordination networks self-assembled from nucleotide monophosphates and lanthanide ions in water; luminescent core-shell nanoparticles are specifically obtained for anionic QDs, which allows their separation from amine-modified QDs..
111. Electron Tomography to Visualise Dislocations in Three-dimension.
112. Hidehisa Hagiwara, Takanori Inoue, Kenji Kaneko, Tatsumi Ishihara, Charge-transfer mechanism in Pt/KTa(Zr)O3 photocatalysts modified with porphyrinoids for water splitting, Chemistry - A European Journal, 10.1002/chem.200901772, 15, 46, 12862-12870, 2009.11, The mechanism of photocatalytic splitting of H2O into H 2 and O2 on Pt/KTa(Zr)O3 modified with various porphyrinoids was investigated. The photocatalytic activity of KTaO3 catalysts is improved by dye modification. Cyanocobalamin (vitamin B 12) is the most effective for improving watersplitting activity, and the formation rates of H2 and O2 achieved values of 575 and 280 μmolgcat -1h-1, respectively. X-ray photoelectron spectroscopy spectra of KTa(Zr)O3 photocatalysts showed that Pt loaded onto dye-modi-fied KTaO3 was slightly oxidized and had low catalytic activity for the H2 oxidation reaction. Photoluminescence (PL) spectra of KTaO3 catalysts suggested that excitation energy was transferred between KTaO3, tetraphenylporphyrinatochromium(III) (Cr-TPP), and the Pt cocatalyst. The wavelength dependence of the activity of dye-modified KTa(Zr)O3 photocatalysts indicated that excitation of both KTa(Zr)O3 and the dye was essential for achieving increased photocatalytic activity. This result suggests that twostep excitation occurred in the dyemodified KTa(Zr)O 3 photocatalysts. Because the lifetime of the charge-separated state increased, this study reveals that modification with porphyrinoids is effective for increasing watersplitting activity..
113. Takahiro Kaseyama, Shinji Takebayashi, Rie Wakabayashi, Seiji Shinkai, Kenji Kaneko, Masayuki Takeuchi, Supramolecular assemblies of polyaniline through cooperative bundling by a palladium-complex-appended synthetic cross-linker, Chemistry - A European Journal, 10.1002/chem.200902305, 15, 46, 12627-12635, 2009.11, A synthetic cross-linker (1) bearing two binding sites for imine moieties in polyaniline has been used to organize polyaniline emeraldine base (EB) or polyaniline emeraldine salt (ES) into aligned assemblies. Complex 1 exhibited highly cooperative binding toward mEB (a repeating unit analogue of EB), for which the association constants K1 and K2 were evaluated to be 2.2×104 and 9.4×105M-1, respectively. 1H NMR studies revealed that the diimine moieties in mEB are recognized cooperatively in anti-conformation by 1. The ordered structures organized from 1 and EB or ES were efficiently formed through supramolecular bundling. These ordered assemblies have a periodicity of 2.5 nm that was confirmed by means of transmittance electron microscopy (TEM) and high-resolution TEM (HRTEM). The cooperative binding would be important for the bundling and alignment of the polymers, as evidenced by the fact that neither reference compounds 2 nor 3 were capable of producing similar assemblies. The electric conductivity of the samples was measured and the results were discussed..
114. Kenji Kaneko, Kazuki Furuya, Ana B. Hungria, Juan Carlos Hernandez-Garrido, Paul A. Midgley, Tsunenobu Onodera, Hitoshi Kasai, Yusuke Yaguchi, Hidetoshi Oikawa, Yohei Nomura, Hiroki Harada, Tatsumi Ishihara, Norio Baba, Nanostructural characterization and catalytic analysis of hybridized platinumphthalocyanine nanocomposites, Microscopy (Oxford, England), 10.1093/jmicro/dfp027, 58, 5, 289-294, 2009.10, Organic crystals, such as phthalocyanine nanocrystal, were successfully hybridized with Pt nanoparticles using a nanohybridization technique. The presence of highly dispersed Pt nanoparticles on the surface of phthalocyanine was confirmed by the combination of transmission electron microscopy and three-dimensional electron tomography. Catalytic activities of hybridized samples with different degrees of dispersions were also examined as oxygen reduction reactivity (ORR) with a linear potential sweep method. It was found that oxygen reduction activity increased with increasing Pt dispersion, and reasonably high ORR was observed on Pt-dispersed phthalocyanine nanocrystal even at 2 wt Pt loading..
115. K. Yamada, Masatoshi Mitsuhara, Satoshi Hata, Y. Miyanaga, Ryo Teranishi, N. Mori, Masashi Mukaida, Kenji Kaneko, Three-dimensional observation of microstructures in Y123 films fabricated by TFA-MOD method, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2009.05.059, 469, 15-20, 1446-1449, 2009.10, We were successful for three-dimensional imaging of microstructures in YBa2Cu3O7-y (Y123) films fabricated by metal organic deposition using trifluoroacetates (TFA-MOD) method. We have reported previously, that a transmission electron microscopy (TEM) analysis clarified microstructures such as Y123 crystal grains and pores in the Y123 films. In order to derive important parameters for enhancement of superconducting properties of the Y123 films, quantitative analyses of those microstructures are required. Then, control of both pores and a-axis oriented grains distribution in the Y123 films are important. However, general TEM images provide only a two-dimensional projection of a three-dimensional object. An electron tomography is an effective technique for three-dimensional structure analysis of various materials. Cross-sectional view specimen for the three-dimensional electron tomography was prepared by focused ion-beam milling equipped with micro-sampling system. A scanning transmission electron microscopy - annular dark field technique was used for the present three-dimensional electron tomography. For the cross-sectional specimen of fired Y123 films, three-dimensional shapes and distributions of both pores and unreacted phases were observed in reconstructed images. Also, morphologies of the Y123 film surface were clearly seen..
116. K. Kaneko, K. Furuya, T. Onodera, H. Kasai, Y. Yaguchi, H. Oikawa, Y. Nomura, H. Harada, T. Ishihara, A. B. Hungria, J.-C. Hernandez-Garrido and P. A. Midgley, Preparation and nanostructural characterization of hybridized platinum/phthalocyanine nanocomposites, Journal of Electron Microscopy, 10.1093/jmicro/dfp027, 58, 5, 289–294, (2009), 2009.06, [URL].
117. H. Shimakoshi, E. Sakumori, K. Kaneko, and Y. Hisaeda, B12-TiO2 Hybrid Catalyst for Dehalogenation of Organic Halides, Chemistry Letters, 38, 5, 468-469, (2009), 2009.05, [URL].
118. H. Maeda, Y. Ito, Y. Haketa, N. Eifuku, E. Lee, M. Lee, T. Hashishin, K. Kaneko, Solvent-Assisted Organized Structures Based on Amphiphilic Anion-Responsive π-Conjugated Systems, Chemistry - A European Journal, 10.1002/chem.200802152, 15, 3706-3719, (2009), 2009.04, [URL].
119. Ko Kitawaki, Kenji Kaneko, K. Inoke, J. C. Hernandez-Garrido, P. A. Midgley, H. Okuyama, M. Uda, Y. Sakka, Fabrication and characterization of TiN-Ag nano-dice, Micron, 10.1016/j.micron.2008.11.004, 40, 3, 308-312, 2009.04, TiN-Ag nanocomposite was synthesized by dc arc-plasma method. Microstructures of TiN-Ag nanocomposite were carefully characterized by powder X-ray diffraction method and transmission electron microscopy, and nano-morphologies by three-dimensional electron tomography. It was found that the surface of nanocrystalline TiN matrix was densely covered by finely dispersed Ag nanoparticles, and it was found that they were physically attached but not chemically bonded from their orientation relationships..
120. Hiromitsu Maeda, Yoshihiro Ito, Yohei Haketa, Nazuki Eifuku, Eunji Lee, Myongsoo Lee, Takeshi Hashishin, Kenji Kaneko, Solvent-assisted organized structures based on amphiphilic anion-responsive π-conjugated systems, Chemistry - A European Journal, 10.1002/chem.200802152, 15, 15, 3706-3719, 2009.04, synthesis of amphiphilic π-conjugated acyclic oligopyrroles and the formation of solvent-assisted aggregates are reported. We have prepared various types of BF2 complexes of 1,3-dipyrrolylpropane-1,3-diones bearing aryl rings substituted with hydrophilic polyethyleneglycol (PEG) chains, both as acyclic anion receptors and as building subunits for organized architectures based on π-π stacking. The formation of supramolecular H-type assemblies of these "amphiphilic" derivatives in aqueous solution was suggested by UV/Vis and fluorescence spectroscopy and further supported by 1H NMR and dynamic light scattering (DLS) analyses. Cryogenic transmission electron microscopy (cryo-TEM) analyses of the aqueous solutions suggest that the fabrication of nanoscale network structures and vesicles depends on the peripheral substituents. The H-aggregates in aqueous solution are sensitive to the conditions required for transformation into monomers through replacement with miscible solvents such as alcohols and into J-type aggregates by water evaporation and freeze-drying procedures. However, they are fairly stable and sustainable to anion binding, whereas on CH2Cl2 extraction they are transformed into other assembled modes but remain in the aqueous solution. The metastable states of affairs for distributions between two immiscible solvents are controlled by the orders of solution preparation; this also suggests that the formation of stable assemblies is assisted by water molecules. Furthermore, assemblies in which the stacking modes depend on the aliphatic side chains are also observed in a nonpolar hydrocarbon solvent..
121. Harunobu Komatsu, Shinji Matsumoto, Shun ichi Tamaru, Kenji Kaneko, Masato Ikeda, Itaru Hamachi, Supramolecular hydrogel exhibiting four basic logic gate functions to fine-tune substance release, Journal of the American Chemical Society, 10.1021/ja8098239, 131, 15, 5580-5585, 2009.04, Logic-gate operations displaying macroscopic outputs are promising systems for the development of intelligent soft materials that can perform effective functions in response to various input patterns. A supramolecular hydrogel comprising the phosphate-type hydrogelator 1 exhibits macroscopic gel - sol behavior in response to four distinct input stimuli: temperature, pH, Ca 2+, and light. We characterized this performance through microscopic, spectroscopic, and rheological measurements. On the basis of its multiplestimulus responsiveness, we constructed gel-based supramolecular logic gates from hydrogelator 1 that demonstrated AND, OR, NAND, and NOR types of stimulus-responsive gel-sol behavior in the presence of various combinations of the four stimuli. Implementation of such logic-gate functions into semiwet soft materials (e.g., supramolecular hydrogels) is an important step toward the design of controlled drug delivery and release systems. Indeed, we demonstrate herein that one of our gel-based supramolecular logic gates is capable of holding and releasing bioactive substances in response to logic triggers. Furthermore, combining our supramolecular gel-based AND logic gate with a photoresponsive supramolecular gel could temporarily modulate the release rate of the bioactive substance..
122. H. Komatsu, S. Matsumoto, S. Tamaru, K. Kaneko, M. Ikeda, I. Hamachi, Supramolecular Hydrogel Exhibiting Four Basic Logic Gate Functions to Fine-tune Substance Release, Journal of the American Chemical Society, 131, 15, 5580–5585, (2009), 2009.03, [URL].
123. K. Kitawaki, K. Kaneko, K. Inoke, J. C. Hernandez, P. A. Midgley, H. Okuyama, M. Uda and Y. Sakka, Fabrication and Characterization of TiN-Ag Nano-Dice, Micron, 40, 308-312, (2009), 2009.02, [URL].
124. Ryuhei Nishiyabu, Nozomi Hashimoto, Ten Cho, Kazuto Watanabe, Takefumi Yasunaga, Ayataka Endo, Kenji Kaneko, Takuro Niidome, Masaharu Murata, Chihaya Adachi, Yoshiki Katayama, Makoto Hashizume, Nobuo Kimizuka, Nanoparticles of Adaptive Supramolecular Networks Self-Assembled from Nucleotides and Lanthanide Ions, Journal of the American Chemical Society, 10.1021/ja8058843, 131, 6, 2151-2158, 2009.02, Amorphous nanoparticles of supramolecular coordination polymer networks are spontaneously self-assembled from nucleotides and lanthanide ions in water. They show intrinsic functions such as energy transfer from nucleobase to lanthanide ions and excellent performance as contrast enhancing agents for magnetic resonance imaging(MRI). Furthermore, adaptive inclusion properties are observed in the self- assembly process: functional materials such as fluorescent dyes, metal nanoparticles, and proteins are facilely encapsulated. Dyes in these nanoparticles fluoresce in high quantum yields with a single exponential decay, indicating that guest molecules are monomerically wrapped in the network. Gold nanoparticles and ferritin were also wrapped by the supramolecular shells. In addition, these nucleotide/lanthanide nanoparticles also serve as scaffolds for immobilizing enzymes. The adaptive nature of present supramolecular nanoparticles provides a versatile platform that can be utilized in a variety of applications ranging from material to biomedical sciences. As examples, biocompatibility and liver-directing characteristics in in vivo tissue localization experiments are demonstrated..
125. Kenji Kaneko, Tetsuro Hata, Tomoharu Tokunaga, Zenji Horita, Fabrication and characterization of supersaturated Al-Mg alloys by severe plastic deformation and their mechanical properties, Materials Transactions, 10.2320/matertrans.MD200813, 50, 1, 76-81, 2009.01, Excess amount of Mg was intentionally added to fabricate supersaturated ultra-fine grained Al-Mg alloy by high pressure torsion (HPT). Their microstructures and mechanical properties were examined by X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and Vickers microhardness test. It was confirmed that the minimum grain size reached ̃40 nm and maximum microhardness 292 Hv at the Mg content with 30mass%. Further increase of the amount of Mg resulted the formation of ß-Al3Mg2 and decrease of microhardness..
126. Munenori Numata, Kenji Kaneko, Hitoshi Tamiaki, Seiji Shinkai, "Supramolecular" amphiphiles created by wrapping poly(styrene) with the helix-forming β-l,3-glucan polysaccharide, Chemistry - A European Journal, 10.1002/chem.200901783, 15, 45, 12338-12345, 2009.01, We have demonstrated that giant polymer micelles with a uniform diameter (ca. 200 nm) can be fabricated by "supramolecular wrapping" of poly(styrene) (PS) with the β-1,3glucan polysaccharide, with the β-1,3glucan fastening the PS chains together in a noncovalent fashion to facilitate the formation of a supramolecular polymer network on the O/W emulsion surface. Various spectroscopic and microscopic investigations have revealed that the inner cores of the micelles are comprised of a hydrophobic PS net-work, whereas the surfaces consist of a hydrophilic β-l,3-glucan layer. Accordingly, functional guest molecules can easily be encapsulated inside the cavity through hydrophobic interactions. The encapsulated molecules can simply be released from the micelle cores by peeling off the β-l,3-glucan shell in a supramolecular manner. As functional groups can be introduced into the glucose side-chain unit in a straightforward manner by chemical modification, the micellar surface can acquire further functions useful for molecular recognition. These results show that the micelles obtained could have applications as novel soft nanoparticles, which would be indispensable not only for nanotechnologies, but also for biotechnologies aimed at gene or drug delivery systems..
127. Youichi Tsuchiya, Shuichi Haraguchi, Kouta Sugikawa, Tomohiro Shiraki, Kenji Kaneko, Seiji Shinkai, Alignment of polysaccharide-SWNT composites by metal-ligand interactions, Chemistry Letters, 10.1246/cl.2009.812, 38, 8, 812-813, 2009.01, The composite of terpyridine-modifled polysaccharide (TPySPG) and single-walled carbon nanotube (SWNT) afforded sheet-like morphologies in the presence of ferric ion. On the basis of TEM images, it was proposed that the sheet-like morphologies are created by the metal-ligand interaction cross-linking TPySPG/SWNT components..
128. Hisashi Shimakoshi, Emiko Sakumori, Kenji Kaneko, Yoshio Hisaeda, B 12-TiO 2 hybrid catalyst for dehalogenation of organic halides, Chemistry Letters, 10.1246/cl.2009.468, 38, 5, 468-469, 2009.01, A cobalamin derivative, cobyrinie acid, was effectively immobilized on TiO 2, and the hybrid TiO 2 was characterized by UV-vis, XPS, MALDI-TOFMS as well as TEM analysis. The hybrid TiO 2 exhibits high reactivity for dehalogenation of various organic halides such as phenethyl bromide, benzyl bromide, and 1,1-bis(4-chlorophenyl)-2,2,2-trichloroethane (DDT) under irradiation with UV light at room temperature..
129. C. Aimé, R. Nishiyabu, R. Gondo, K. Kaneko and N. Kimizuka, Controlled self-assembly of nucleotide-lanthanide complexes : specific formation of nanofibers from dimeric guanine nucleotides, Chem. Commun. , (2008) pp.6534 - 6536, 2008.12, [URL].
130. Kouta Sugikawa, Munenori Numata, Kenji Kaneko, Kazuki Sada, Seiji Shinkai, Alternate layer-by-layer adsorption of single- and double-walled carbon nanotubes wrapped by functionalized β-1,3-glucan polysaccharides, Langmuir, 10.1021/la802211q, 24, 23, 13270-13275, 2008.12, A great deal of attention has been focused on exploiting novel methods to fabricate thin carbonaceous capsules from multiple components for advanced materials. A layer-by-layer (LbL) method is therefore being introduced to synthesize thin and multi-carbon nanotube (CNT)-based hollow capsules from CNT complexes with cationic or anionic complementarily functionalized β-1,3-glucans as building-blocks. These ionic β-1,3-glucans wrap around single-walled carbon nanotubes (SWNTs) and double-walled carbon nanotubes (DWNTs) to form water-soluble complexes with ionic groups on their exterior surface. Alternate self-assembly of these CNT complexes on the silica particles is demonstrated in solution by electrostatic interactions. The LbL adsorption processes were carefully monitored by ß-potential measurements, frequency shifts of a quartz crystal microbalance (QCM), and electron micrographs. Silica particles were then dissolved away by HF acid to obtain CNT-based hollow capsules composed of SWNTs and DWNTs. We believe that these novel surface adsorption methods are useful for potential design of CNT-based advanced functional materials..
131. J. H. Sharp, J. S. Barnard, K. Kaneko, K. Higashida and P. A. Midgley , Dislocation tomography made easy: a reconstruction from ADF STEM images obtained using automated image shift correction, J. Phys.: Conf. Ser., 126, 012013, (2008), 2008.11.
132. Masaki Tanaka, Masaki Honda, Masatoshi Mitsuhara, Satoshi Hata, Kenji Kaneko, Kenji Higashida, Erratum
Three-dimensional observation of dislocations by electron tomography in a silicon crystal (Materials Transactions (2008) 49:9 (1953-1956)), Materials Transactions, 10.2320/matertrans.E2008002, 49, 11, 2753, 2008.11.
133. K. Sugikawa, M. Numata, K. Kaneko, K. Sada, and S. Shinkai, Alternate Layer-by-Layer Adsorption of Single- and Double- Walled Carbon Nanotubes Wrapped by Functionalized beta-1,3-Glucan
Polysaccharides, Langmuir, 24, 23, 13270–13275, (2008), 2008.10, [URL].
134. Masaki Tanaka, Kenji Higashida, Kenji Kaneko, Satoshi Hata, Masatoshi Mitsuhara, Crack tip dislocations revealed by electron tomography in silicon single crystal, Scripta Materialia, 10.1016/j.scriptamat.2008.06.042, 59, 8, 901-904, 2008.10, Crack tip dislocations in silicon single crystals have been observed by a combination of annular dark-field scanning transmission electron microscopy and computed tomography. A series of images was acquired by maintaining the diffraction vector parallel to that of crack propagation to achieve sharp images of the dislocations. The observed dislocations were reconstructed by a filtered back-projection, and exhibited three-dimensional configurations of overlaid dislocations around the crack tip..
135. S. Tamesue, M. Numata, K. Kaneko, T. D. James and S. Shinkai, Hierarchical carbon nanotube assemblies created by sugar–boric or boronic acid interactions, Chem. Commun. , 37, 4478–4480, (2008), 2008.09, [URL].
136. Masaki Tanaka, Masaki Honda, Masatoshi Mitsuhara, Satoshi Hata, Kenji Kaneko, Kenji Higashida, Three-dimensional observation of dislocations by electron tomography in a silicon crystal, Materials Transactions, 10.2320/matertrans.MAW200828, 49, 9, 1953-1956, 2008.09, Dislocations in a silicon single crystal introduced by three point-bending at a high temperature were observed by electron tomography in annular dark field-scanning transmission electron microscopy (ADF-STEM). Commercially available P type (001) single crystal wafers were employed. An ADF STEM tilt series was acquired from -60° to +60° in tilt range with 2° in tilt step. The diffraction vector was maintained close to g(hkl) = 220 during the acquisition by adjusting the [110] direction of the sample parallel to the tilt axis of the holder. The observed dislocations were reconstructed by simultaneous interactive reconstruction technique, exhibiting a 3-D configuration of dislocations introduced by the three-point bending..
137. S. Haraguchi, M. Numata, K. Kaneko and S. Shinkai, Immobilization of polythiophene chirality induced by a helix-forming beta-1,3 glucan polysaccharide (schizophyllan) through sol-gel reaction, Bulletin of the Chemical Society of Japan, Vol 81. No 8 (2008) pp. 1002-1006, 2008.08, [URL].
138. T. Tokunaga, K. Kaneko and Z. Horita, Production of aluminum-matrix carbon nanotube composite using high pressure torsion, Material Science and Engineering A, 490, 1-2, 300-304, (2008), 2008.08, [URL].
139. M. Tanaka, K. Higashida, K. Kaneko, S. Hata, M. Mitsuhara, Crack Tip Dislocations Revealed by Electron Tomography in Silicon Single Crystal, Scripta Materialia, Vol. 59 (2008) pp. 901–904, 2008.08, [URL].
140. Shuichi Haraguchi, Munenori Numata, Kenji Kaneko, Seiji Shinkai, Immobilization of polythiophene chirality induced by a helix-forming β-1,3-glucan polysaccharide (schizophyllan) through sol-gel reaction, Bulletin of the Chemical Society of Japan, 10.1246/bcsj.81.1002, 81, 8, 1002-1006, 2008.08, It is known that an achiral water-soluble polythiophene (PT-1) is chirally twisted by complexation with a natural helix-forming polysaccharide, shizophyllan (SPG). We found that the chirality can be immobilized by sol-gel reaction of tetraethoxysilane (TEOS) with benzylamine as a catalyst ("solution mechanism"), where SPG acts not only as a chirality inducer for PT-1 but also as a chemical glue to adsorb silica particles onto the composite surface. When a complex with amine-appended SPG (SPG-NH) was used as a template, the sol-gel reaction proceeded according to the "surface mechanism," where silica particles were formed mainly on the composite surface due to the catalytic effect of the covalently bound amino groups and thus the reaction conditions became milder. It was confirmed that under the "surface mechanism" the chemical and physical properties of the original PT-1/SPG-NH composite are maintained more efficiently..
141. Tomoharu Tokunaga, Kenji Kaneko, Zenji Horita, Production of aluminum-matrix carbon nanotube composite using high pressure torsion, Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing, 10.1016/j.msea.2008.02.022, 490, 1-2, 300-304, 2008.08, In this study, an Al-based composite containing carbon nanotubes (CNTs) was fabricated using a process of severe plastic deformation through high pressure torsion (HPT). Neither heating nor sintering was required with the HPT process so that an in situ consolidation was successfully achieved at ambient temperature with 98% of the theoretical density. A significant increase in hardness was recorded through straining by the HPT process. When the composite was pulled in tension, the tensile strength of more than 200 MPa was attained with reasonable ductility. Transmission electron microscopy showed that the grain size was reduced to ∼100 nm and this was much smaller than the grain size without CNTs and the grain size reported on a bulk sample. High resolution electron microscopy revealed that CNTs were present at grain boundaries. It was considered that the significant reduction in grain size is attributed to the presence of CNTs hindering the dislocation absorption and annihilation at grain boundaries..
142. Y. Nomura, T. Ishihara, Y. Hata, K. Kitawaki, K. Kaneko and H. Matsumoto, Nanocolloid Pd-Au as catalyst fo the direct synthesis of hydrogen peroxide from H2 and O2, ChemSusChem, 1, 7, 619-621, (2008), 2008.07, [URL].
143. Y. Hayashi, T. Fujita, T. Tokunaga, K. Kaneko, M. Tanemura, T. Butler, N. Rupesinghe, J.D. Carey, S.R.P. Silva, K.B.K. Teo, G.A.J. Amaratunga, Microstructure and local magnetic induction of segmented and alloyed Pd/Co nanocomposites encapsulated inside vertically aligned multiwalled carbon nanotubes, Diamond and Related Materials, 17, 7-10, 1525-1528, (2008), 2008.07, [URL].
144. Yasuhiko Hayashi, T. Fujita, T. Tokunaga, Kenji Kaneko, M. Tanemura, T. Butler, N. Rupesinghe, J. D. Carey, S. R P Silva, K. B K Teo, G. A J Amaratunga, Microstructure and local magnetic induction of segmented and alloyed Pd/Co nanocomposites encapsulated inside vertically aligned multiwalled carbon nanotubes, Diamond and Related Materials, 10.1016/j.diamond.2008.03.012, 17, 7-10, 1525-1528, 2008.07, We have successfully synthesized the Co/Pd magnetic and nonmagnetic multisegment nanowires encapsulated inside multiwalled carbon nanotubes (MWCNTs) by using Co and Pd thin-layers deposited on Si substrate by microwave plasma enhanced chemical vapor deposition. Energy dispersive X-ray spectroscopy revealed that MWCNTs were encapsulated with Co and Pd nanowires, separately, at the tube top and the bottom of Co nanowire, respectively. The face-centered-cubic (fcc) structure of Co nanowires was confirmed by a selected area diffraction pattern. We proposed a fruitful description for the encapsulating mechanisms of both Co and Pd multisegment nanowires. The component of magnetic induction from Co region, not Pd region, was then estimated to be 1.2 ± 0.1 T, based on results of off-axis electron holography, which is lower than the expected saturation magnetization of fcc bulk Co of 1.7 T. We proposed a fruitful description for the mechanisms of reduced magnetic induction from Co nanowires..
145. Yohei Nomura, Tatsumi Ishihara, Yuiko Hata, Kotaro Kitawaki, Kenji Kaneko, Hiroshige Matsumoto, Nanocolloidal Pd-Au as catalyst for the direct synthesis of hydrogen peroxide from H2 and O2, ChemSusChem, 10.1002/cssc.200800029, 1, 7, 619-621, 2008.07, Every colloid has a gold lining: The direct synthesis of hydrogen peroxide from hydrogen and oxygen is attracting much interest as an alternative method for producing H2O2. Pd-Au bimetallic nanocolloid exhibits high catalytic activity for the direct synthesis of H2O2 from H2 and O2. The high activity results from the presence of Au on the colloid surface which suppresses the decomposition of H2O2 in the presence of H2..
146. T. Morikawa, K. Kaneko, K. Higashida, D. Kinoshita, M. Takenaka and Y. Kawamura, The Fine-Grained Structure in Magnesium Alloy Containing Long-Period Stacking Order Phase, Materials Transactions, 49, 6, 1294-1297, (2008), 2008.06, [URL].
147. Tatsuya Morikawa, Kenji Kaneko, Kenji Higashida, Daisuke Kinoshita, Masanori Takenaka, Yoshihito Kawamura, The fine-grained structure in magnesium alloy containing long-period stacking order phase, Materials Transactions, 10.2320/matertrans.MC2007110, 49, 6, 1294-1297, 2008.06, Microstructural characteristics of warm-extruded magnesium alloy (Mg 97Zn1Y2) containing long-period stacking order (LPSO) phase has been investigated using SEM and TEM as the first step to understand the effect of warm-extrusion on its mechanical property. Particular attention has been paid on the microstructural change in the hep matrix caused by warm extrusion. The microstructure developed by the warm extrusion at 623 K consists of elongated grains with fine-lamellae of LPSO phase and fine-grained matrix of hep phase. The grain size of the hep matrix observed on the cross section perpendicular to the extruding direction was about 1 urn, indicating that remarkable grain refinement was occurred during the extrusion since the grain size of as-cast alloy was around 0.5 mm. Those fine grains in the extruded alloy included abundant stacking faults, and HAADF-STEM observation revealed that the stacking faults were enriched by Zn and Y. In addition, grain boundaries were also enriched by those solute elements, which must contribute to stabilizing such fine- grained structure..
148. T. Tokunaga, K. Kaneko, K. Sato and Z. Horita, Microstructure and Mechanical Properties of Aluminum-fullerene Composite Fabricated by High Pressure Torsion, Scripta Materialia, 58, 9, 735-738, (2008), 2008.05, [URL].
149. Tomoharu Tokunaga, Kenji Kaneko, Keisuke Sato, Zenji Horita, Microstructure and mechanical properties of aluminum-fullerene composite fabricated by high pressure torsion, Scripta Materialia, 10.1016/j.scriptamat.2007.12.010, 58, 9, 735-738, 2008.05, An Al-based composite containing fullerene (a mixture of C60 and C70) was fabricated using a process of severe plastic deformation through high pressure torsion (HPT) for the first time. Neither heating nor sintering was required during the HPT process, so in situ consolidation was successfully achieved at ambient temperature. Vickers microhardness reached almost 120 Hv, the composite had a tensile strength of more than 253 MPa with 0.18 nominal strain, and the grain size was reduced to ∼80 nm..
150. K. Ishii, R. Ozaki, K. Kaneko, M. Masuda , Corrosion prevention of aluminum heat exchanger in deoxidized pure water, Journal of The Japan Institute of Metals, 72, 4, 299-304, (2008), 2008.04.
151. M. Numata, K. Sugikawa, K. Kaneko and S. Shinkai, Creation of Hierarchical Carbon Nanotube Assemblies through Alternative Packing of Complementary Semi-artificial beta-1,3-Glucan/Carbon Nanotube Composites, Chemistry a European Journal, 14, 8, 2398-2404, (2008), 2008.04, [URL].
152. Katsuya Ishii, Ryota Ozaki, Kenji Kaneko, Masataka Masuda, Corrosion prevention of aluminum heat exchanger in deoxidized pure water, Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, 10.2320/jinstmet.72.299, 72, 4, 299-304, 2008.04, In the development of the adsorption refrigerator, one of the most serious concern is to protect the corrosion from aluminum heat exchanger in deoxidized water. Two kinds of corrosion protection methods were discussed. One was to form an SiO2 Sol/Gel film of which thickness is about 2 μm on the aluminum surface and the other was to add small amount of SiO3 2- in the deoxidized water. When an aluminum sheet of A1N99 coated with the SiO2 Sol/Gel film on the surface was immersed in deoxidized water, corrosion did not occur during 10000 h. In the case of actual aluminum heat exchanger with the same film on the surface, although corrosion did not happen during the first 1800 h, it came out suddenly after 1800 h. From the result of this corrosion performance, the aluminum heat exchanger with the SiO2 Sol/Gel film is not considered to be proper for the application to the refrigerator. The effect of SiO3
2- in water to protect the corrosion was investigated and it was confirmed that corrosion from the aluminum heat exchanger with the SiO2 Sol/Gel film did not occur for at least 5000 h in the deoxidized water with 5 ppm SiO3 2-..
153. Munenori Numata, Kouta Sugikawa, Kenji Kaneko, Seiji Shinkai, Creation of hierarchical carbon nanotube assemblies through alternative packing of complementary semi-artificial β-1,3-glucan/carbon nanotube composites, Chemistry - A European Journal, 10.1002/chem.200701205, 14, 8, 2398-2404, 2008.03, Much attention has been focused on exploiting novel strategies for the creation of hierarchical polymer assemblies by the control of the assembling number or the relative location among neighboring polymers. We here propose a novel strategy toward the creation of "hierarchical" single-walled carbon nanotube (SWNT) architectures by utilizing SWNT composites with cationic or anionic complementary semiartificial β-1,3-glucans as "building blocks". These β-1,3-glucans are known to wrap SWNTs helically, to create one-dimensional superstructural composites. If the cationic composite is neutralized by an anionic composite, a well ordered SWNT-based sheet structure was created. Transmission electron microscopy (TEM) observation revealed that this sheet structure is composed of highly-ordered fibrous assemblies of SWNTs. This suggests that the cationic and anionic composites are tightly packed through electrostatic interactions. Moreover, both of the final assembly structures are readily tunable by adjusting the cation/anion ratio. The self-assembling modulation of functional polymers is associated with the progress in ultimate nanotechnologies, thus enabling us to create numerous functional nanomaterials. We believe, therefore, that the present system will extend the frontier of SWNT research to assembly chemistry including "hierarchical" superstructures..
154. Kenji Kaneko, Three-dimensional electron tomography by transmission electron microscopy, Yosetsu Gakkai Shi/Journal of the Japan Welding Society, 77, 2, 5-8, 2008.03.
155. Kenji Kaneko, K. Inoke, K. Sato, K. Kitawaki, H. Higashida, I. Arslan, P. A. Midgley, TEM characterization of Ge precipitates in an Al-1.6 at% Ge alloy, Ultramicroscopy, 10.1016/j.ultramic.2007.04.020, 108, 3, 210-220, 2008.02, The growth mechanism and morphology of Ge precipitates in an Al-Ge alloy was characterized by a combination of in-situ transmission electron microscopy, high-resolution transmission electron microscopy and three-dimensional electron tomography. Anisotropic growth of rod-shaped Ge precipitates was observed by in-situ transmission electron microscopy over different time periods, and faceting of the precipitates was clearly seen using high-resolution transmission electron microscopy and three-dimensional electron tomography. This anisotropic growth of rod-shaped Ge precipitates was enhanced by vacancy concentration as proposed previously, but also by surface diffusion as observed during the in-situ experiment. Furthermore, a variety of precipitate morphologies was identified by three-dimensional electron tomography..
156. Y. Harai, M. Kai, K. Kaneko, Z. Horita and T. G. Langdon, Microstructural and Mechanical Characteristics of AZ61 Magnesium Alloy Processed by High-Pressure Torsion, Materials Transactions, Vol.49 No.1 (2008) pp.76-83, 2008.01.
157. K. Kaneko, K. Inoke, K. Sato, K. Kitawaki, H. Higashida, I. Arslan and P. A. Midgley, TEM characterization of Ge precipitates in an Al-1.6 at.% Ge alloy, Ultramicroscopy, 108, 3, 210-220, (2008), 2008.01, [URL].
158. Tsuyoshi Minami, Kenji Kaneko, Takeshi Nagasaki, Yuji Kubo, Isothiouronium-based amphiphilic gold nanoparticles with a colorimetric response to hydrophobic anions in water
a new strategy for fluoride ion detection in the presence of a phenylboronic acid, Tetrahedron Letters, 10.1016/j.tetlet.2007.11.120, 49, 3, 432-436, 2008.01, Gold nanoparticles modified with isothiouronium-derived amphiphile units 1 were prepared by the reduction of AuCl4 - (n - C8 H17)4 N+ with NaBH4 in the presence of bis(5-(N-(2-(2-methoxyethoxy)ethyl)-N-methyl-S-isothiouronio)pentyl) disulfide 2. The obtained nanoparticles 1 showed a selective coloration for hydrophobic anions in water, possibly due to an anion exchange and subsequent aggregation. On the basis of this observation, the detection of F- in water has been achieved using 3-nitrophenylboronic acid as a mediator at pH 5.5, thereby providing a new strategy for the design of a F- sensory system..
159. Yosuke Harai, Masaaki Kai, Kenji Kaneko, Zenji Horita, Terence G. Langdon, Microstructural and mechanical characteristics of AZ61 magnesium alloy processed by high-pressure torsion, Materials Transactions, 10.2320/matertrans.ME200718, 49, 1, 76-83, 2008.01, Experiments were conducted on an AZ61 magnesium alloy to evaluate the microstructural characteristics and the mechanical properties after processing by High-Pressure Torsion (HPT). The results show that processing by HPT produces excellent grain refinement with average grain sizes of ∼0.22 and ∼0.11 urn after processing at 423 K and room temperature, respectively. Tensile testing after HPT revealed the potential for achieving superplastic elongations with a maximum recorded elongation of 620% when testing at a temperature of 473 K. Using microhardness measurements, it is demonstrated that the the microstructure gradually evolves with increasing torsional straining in HPT so that ultimately there is a reasonably homogeneous structure across the disk..
160. Carole Aimé, Ryuhei Nishiyabu, Ryosuke Gondo, Kenji Kaneko, Nobuo Kimizuka, Controlled self-assembly of nucleotide-lanthanide complexes
Specific formation of nanofibers from dimeric guanine nucleotides, Chemical Communications, 10.1039/b815779k, 48, 6534-6536, 2008.01, Monomeric and dimeric guanine nucleotides monophosphate spontaneously self-assemble into nanoparticles and nanofibers in the presence of lanthanide ions, which reflects differences in the unit coordination structures and their hierarchical assembly..
161. J. H. Sharp, J. S. Barnard, Kenji Kaneko, K. Higashida, P. A. Midgley, Dislocation tomography made easy
A reconstruction from ADF STEM images obtained using automated image shift correction, Journal of Physics: Conference Series, 10.1088/1742-6596/126/1/012013, 126, 2008.01, After previous work producing a successful 3D tomographic reconstruction of dislocations in GaN from conventional weak-beam dark-field (WBDF) images, we have reconstructed a cascade of dislocations in deformed and annealed silicon to a comparable standard using the more experimentally straightforward technique of STEM annular dark-field imaging (STEM ADF). In this mode, image contrast was much more consistent over the specimen tilt range than in conventional weak-beam dark-field imaging. Automatic acquisition software could thus restore the correct dislocation array to the field of view at each tilt angle, though manual focusing was still required. Reconstruction was carried out by sequential iterative reconstruction technique using FEI's Inspect3D software. Dislocations were distributed non-uniformly along cascades, with sparse areas between denser clumps in which individual dislocations of in-plane image width 24 nm could be distinguished in images and reconstruction. Denser areas showed more complicated stacking-fault contrast, hampering tomographic reconstruction. The general three-dimensional form of the denser areas was reproduced well, showing the dislocation array to be planar and not parallel to the foil surfaces..
162. Shingo Tamesue, Munenori Numata, Kenji Kaneko, Tony D. James, Seiji Shinkai, Hierarchical carbon nanotube assemblies created by sugar-boric or boronic acid interactions, Chemical Communications, 10.1039/b808599d, 37, 4478-4480, 2008.01, We previously found that polysaccharide "schizophyllan (SPG)" can entrap as-grown and cut single-walled carbon nanotubes (as-SWNTs and c-SWNTs, respectively): we here reported that the c-SWNT-s-SPG (single stranded SPG) composites thus obtained can be aligned regularly using the covalent bond formation between boric acid or boronic acid derivatives and the 4,6-dihydroxyl group of the glucose side-chain unit..
163. K. Kaneko, K. Sato, Z Horita and K. Inoke, Characterization of precipitates by three-dimensional electron tomography, Material Science Forum, 561-565, 3, 2009-2012, (2007), 2007.12.
164. Corrosion of 3003 Aluminum Alloy in Deoxidized Water, K. Ishii, R. Ozaki, K. Kaneko, M. Masuda, Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals 71 (12), pp. 1080-1083 .
165. Katsuya Ishii, Ryota Ozaki, Kenji Kaneko, Masataka Masuda, Corrosion of 3003 aluminum alloy in deoxidized water, Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, 10.2320/jinstmet.71.1080, 71, 12, 1080-1083, 2007.12, Corrosion test of AIN99 (99.99% pure aluminum) and A3003 (Al-Mn Alloy) in deoxidized (O2 <0.1 ppm) pure water was conducted at the different temperatures. Although the incubation period, from the beginning of the test until the corrosion rate dramatically increased, was varied depending on temperature, it was not affected much by the composition of the material. It was also found that the corrosion rate changed remarkably depending on the temperature and the composition of the material after the incubation period; the corrosion rate of AIN99 was about three times faster than that of A3003. This was not caused by the speed of reaction of aluminum and water on the aluminum surface. AIN99 corroded all over the surface, while A3003 corrodes partially because Mn and Cu are distributed and the corroded area is small. However, the amount of corrosion was almost the same at the saturated condition, whereas the corrosion rate changes depending on the temperature and the composition of the material. This was because the corrosion continued until corrosion products accumulate to the same level on the surface. Accordingly, it become clear that when corrosion rate was fast, corrosion time was short; on the: other hand, corrosion time was long when corrosion rate was slow..
166. K. Kaneko, Three-dimensional nano characterization of materials by TEM, Proceedings of 38th fall meeting of Korean Society of Microscopy, 29-34, (2007), 2007.11.
167. S. Tanemura, L. Miao, Y. Kajino, Y. Itano, M. Tanemura, S. Toh, K. Kaneko, Y. Mori , Fabrication and optical characterization of vanadium oxide nano-particulates thin film, Journal of Materials Science: Materials in Electronics, Vol.18 (2007) pp.S43-S46 , 2007.10, [URL].
168. L. Miao, S. Tanemura, T. Watanabe, M. Tanemura, S. Toh, Kenji Kaneko, Y. Sugahara, T. Hirayama, Epitaxial growth of Ba8Ga16Ge30 clathrate film on Si substrate by RF helicon magnetron sputtering with evaluation on thermoelectric properties, Applied Surface Science, 10.1016/j.apsusc.2007.07.065, 254, 1 SPEC. ISS., 167-172, 2007.10, Epitaxial Ba8Ga16Ge30 clathrate thin films were successfully grown on Si substrate by using helicon magnetron sputtering. The (1 0 0) lattice of Ba8Ga16Ge30 was identified grown on four Si(2 0 0) lattices in small mismatch (0.1%). Both the color of samples and XRD results suggest 600 °C is the optimal substrate temperature for the growth of high quality Ba-Ga-Ge clathrate film on Si substrates. High Seebeck coefficients and electrical resistivities for the deposited clathrate thin films in comparison with those of bulk are obtained. The high crystal quality and thermionic effects in heterostructures may contribute to the larger Seebeck coefficients, while the increasing of interface scattering for electrons probably is the reason for large electrical resistivities. Although the thermoelectric (TE) results are not ideal as designed, our results are significant due to the first successful work on epitaxial growth of Ba8Ga16Ge30 clathrate thin films on Si substrate with large Seebeck coefficient..
169. Sakae Tanemura, L. Miao, Y. Kajino, Y. Itano, M. Tanemura, S. Toh, Kenji Kaneko, Y. Mori, Fabrication and optical characterization of vanadium oxide nano-particulates thin film, Journal of Materials Science: Materials in Electronics, 10.1007/s10854-007-9182-z, 18, SUPPL. 1, 43-46, 2007.10, We have succeeded to fabricate the thin films (350 nm in total thickness) consisting of semiconducting Vanadium-oxide (VO 0.9+x (0.30 ≤ x < 0.37)) nano-particles with 3.47 nm in averaged diameter by using the combined magnetron sputtering and gas aggregation methods. The optical band gap of the film is evaluated as 3.88 eV under the ad hoc assumption of direct allowed optical transition mode by spectroscopic ellipsometry. This value is expanded by 0.18 eV comparing with the estimated VO bulk value. The widening of band gap might be due to the lattice strain and/or the quantum confinement effect of the composed nano-particles..
170. K. Yamada, N. Mori, K. Tada, T. Tanaka, Ryo Teranishi, Masashi Mukaida, S. Toh, Kenji Kaneko, T. Izumi, Y. Shiohara, Transmission electron microscopy studies of YBCO films fabricated by advanced TFA-MOD process, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2007.04.289, 463-465, SUPPL., 717-721, 2007.10, The advanced metal organic deposition using trifluoroacetates (TFA-MOD) is one of the most promising methods for producing superconducting coated conductors. In order to form highly grain aligned YBa2Cu3O7-δ (Y123) films with high JC, it is important to control the microstructures of the films. In the present work, Y123 films were grown by the advanced TFA-MOD method on CeO2 layered LaAlO3 (LAO) substrates. Quenched films were prepared by cooling rapidly during the crystallization stage, and their cross-sectional microstructures were investigated by transmission electron microscopy (TEM). The bright-field images (BFIs) showed existence of some grains, precipitates and their interfaces in the film. Selected area electron diffraction patterns (SAEDPs) were taken from various regions, and a-axis and/or c-axis-oriented structures, amorphous structures, etc. were observed. In addition, Y123 grains, BaF2, CuO and Y2Cu2O5 grains were clarified by the scanning transmission electron microscopy-energy dispersive X-ray spectroscopy (STEM-EDS) analyses..
171. L. Miao, Y. Ieda, S. Tanemura, Y. G. Cao, M. Tanemura, Y. Hayashi, S. Toh, Kenji Kaneko, Synthesis, microstructure and photoluminescence of well-aligned ZnO nanorods on Si substrate, Science and Technology of Advanced Materials, 10.1016/j.stam.2007.02.012, 8, 6, 443-447, 2007.09, Well-aligned zinc oxide (ZnO) nanorods were densely grown on Si substrate using ZnO thin-film seed layer without any catalysts and/or additives by a simple solid-vapour phase thermal sublimation technique. The growth mechanism can be interpreted as self-catalyst of zinc particles based on vapour-solid (VS) mechanism. High-resolution transmission electron microscopy (HRTEM) image and selected area electron diffraction (SAED) pattern confirmed that the single-crystalline growth of the nanorods were preferentially along c-axis of hexagonal crystal system. High-crystal quality ZnO nanorods with strong near band edge emission centred at 380 nm can be achieved on Si substrate by the introduction of sufficient oxygen during the nanorod growth processing..
172. Keisuke Sato, Kenji Kaneko, Tomoharu Tokunaga, Yasuhiko Hayashi, Zenji Horita, Facile fabrication and structural studies of filtered Ge nanowires from aged Al-Ge alloy, Scripta Materialia, 10.1016/j.scriptamat.2007.03.054, 57, 3, 281-284, 2007.08, Single crystalline Ge nanowires have been fabricated by filtration of rod-shaped Ge precipitates from aged Al-Ge alloy using HCl solution. The diameter of the Ge nanowires ranged from 30 to 100 nm when the aging conditions of the Al-Ge alloy was altered. The Ge nanowires grow preferentially in the [1 1 0] direction, which is the same as observed earlier for rod-shaped Ge precipitates in the aged Al-Ge alloy..
173. L. Miao, Y. Ina, S. Tanemura, T. Jiang, M. Tanemura, K. Kaneko, S. Toh and Y. Mori, Fabrication and photochromic study of titanate nanotubes loaded with silver nanoparticles, Surface Science, Vol.603 No.13 (2007) pp.2792–2799, 2007.07, [URL].
174. A. Umemoto, K. Hayashi, K. Hayano, N. Saito, K. Kaneko and K. Nakashima, Effect of Mo Powder Surface Condition on Fabrication of Mo-SiO2 Functionally Graded Materials with Slipcasting Method, Ceramic Transactions, Vol.198 (2007) pp.219-224, 2007.07.
175. L. Miao, Y. Ina, S. Tanemura, T. Jiang, M. Tanemura, Kenji Kaneko, S. Toh, Y. Mori, Fabrication and photochromic study of titanate nanotubes loaded with silver nanoparticles, Surface Science, 10.1016/j.susc.2006.12.062, 601, 13, 2792-2799, 2007.07, Pure anatase-TiO2 and/or titanate nanotubes, photochromic Ag loaded titanium dioxide nanotubes (TNTs) and AgCl loaded titanate nanotubes were synthesized by hydrothermal method. The pH value during the neutralization process plays a crucial role in controlling the morphology and composition of the nanotubes. All these nanotubes were confirmed by XRD, TEM, EDS and XPS analysis. Most of them have open ends with inner/outer diameters of 7/10 nm and several hundred nanometers in length. For photochromic behavior in the case of AgCl-titanate nanotubes, the red color can be clearly observed after irradiation by red light, while the yellow, green, blue ones displayed pale black after the corresponding irradiation. On the other hand, Ag loaded TNT sample exhibited multicolor photochromism corresponding to that of incident light. The photoreduction of silver halide to Ag particle in the case of loaded AgCl particles and a particle-plasmon-assisted electron transfer from Ag nanoparticles to TiO2 in the case of loaded Ag particles are considered to be responsible for this different behavior..
176. Tatsumi Ishihara, Yuiko Hata, Yohei Nomura, Kenji Kaneko, Hiroshige Matsumoto, Pd-Au bimetal supported on rutile-TiO 2 for selective synthesis of hydrogen peroxide by oxidation of H 2 with O 2 under atmospheric pressure, Chemistry Letters, 10.1246/cl.2007.878, 36, 7, 878-879, 2007.07, Rutile TiO 2 support is effective for increasing the formation rate as well as selectivity to H 2O 2. A great enhancement in the H 2O 2 formation rate and selectivity is achieved by controlling the particle size of Pd-Au (7:3 in weight ratio) alloy, and the average size of 18 nm exhibits the high selectivity to H 2O 2 under atmospheric pressure..
177. S. Malik, N. Fujita, P. Mukhopadhyay, Y. Goto, K. Kaneko, T. Ikeda, S. Shinkai, Creation of 1D [60]fullerene superstructures and its polymerization by -ray irradiation, Journal of Materials Chemistry, Vol.17 (2007) pp.2454-2458, 2007.06, [URL].
178. Katsuya Ishii, Ryota Ozaki, Kenji Kaneko, Hisaaki Fukushima, Masataka Masuda, Continuous monitoring of aluminum corrosion process in deaerated water, Corrosion Science, 10.1016/j.corsci.2006.12.015, 49, 6, 2581-2601, 2007.06, A device was developed for the continuous measurement of the open circuit corrosion rate of aluminum in deaerated water from hydrogen pressure, resulted from the cathodic reaction. Corrosion rate of aluminum coated by the passive oxide film was examined with respect to the corrosion phenomena using this device. From the results, it was found that the corrosion rate was dependent not only on the deterioration of the film, but also on the formation of pits and of corrosion products on the film. Furthermore, the deterioration of the film was independent on the pH of the water. The pits were most probably formed by the evolution of hydrogen gas at the cathode underneath the film followed by the formation of Al (OH)4
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179. M. Shirakawa, N. Fujita, T. Tani, K. Kaneko, M. Ojima, A. Fujii, M. Ozaki, and S. Shinkai, Organogels of 8-Quinolinol Metal(II) Chelate Derivatives Which Show the Electron- and Light-Emitting Properties, Chemistry A European Journal, Vol.13 No.15 (2007) pp.4155-4162, 2007.05, [URL].
180. Y. Hayashi, T. Fujita, T. Tokunaga, K. Kaneko, T. Butler, N. Rupesinghe, J.D. Carey, S.R.P. Silva and G.A.J. Amaratunga, Encapsluation of Co and Pd multi-metal nanowires inside multiwalled carbon nanotubes by microwave plasma chemical vapor deposition, Diamond and Related Materials, Vol.16 No.4-7 (2007) pp.1200-1203, 2007.04, [URL].
181. Yasuhiko Hayashi, T. Fujita, T. Tokunaga, Kenji Kaneko, T. Butler, N. Rupesinghe, J. D. Carey, S. R P Silva, G. A J Amaratunga, Encapsluation of Co and Pd multi-metal nanowires inside multiwalled carbon nanotubes by microwave plasma chemical vapor deposition, Diamond and Related Materials, 10.1016/j.diamond.2006.11.039, 16, 4-7 SPEC. ISS., 1200-1203, 2007.04, We report the synthesis of multiwalled carbon nanotubes (MWCNTs) encapsulated with Co/Pd magnetic and nonmagnetic multi-metal nanowires using Co and Pd thin-layers deposited on Si substrate by microwave plasma enhanced chemical vapor deposition using a bias-enhanced growth method. Detailed structural and compositional investigations of these metal nanowires inside MWCNTs were carried out by scanning electron microscopy and transmission electron microscopy to elucidate the growth mechanisms. Energy dispersive X-ray spectroscopy revealed that MWCNTs were encapsulated with Co and Pd nanowires, separately, at the tube top and the bottom of Co nanowire, respectively. The face-centered-cubic (fcc) structure of Co nanowires was confirmed by a selected area diffraction pattern. We proposed a fruitful description for the encapsulating mechanisms of both Co and Pd multi-metal nanowires..
182. Yoichi Takeda, Naohiko Shimada, Kenji Kaneko, Seiji Shinkai, Kazuo Sakurai, Ternary complex consisting of DNA, polycation, and a natural polysaccharide of schizophyllan to induce cellular uptake by antigen presenting cells, Biomacromolecules, 10.1021/bm0611937, 8, 4, 1178-1186, 2007.04, A natural polysaccharide called schizophyllan (SPG) can form a complex with polynucleotides, and the complex has been shown to deliver biofunctional short DNAs such as antisense DNAs and CpG-DNAs. Although it is a novel and efficient method, there is a drawback: attachment of homo-polynucleotide tails [for example, poly-(dA) or poly(C)] to the end of DNA is necessary to stabilize the complex, because DNA heterosequences cannot bind to SPG. The aim of this paper is to present an alternative method in which SPG/DNA complexes can be made without using the tails. The basic strategy is as follows: since SPG can form hydrophobic domains in aqueous solutions, hydrophobic objects should be encapsulated by this domain. DNA alone is highly hydrophilic; however, once DNA/polycation complexes are made, they should be included by the SPG hydrophobic domain. The aim of this paper is to prove the formation of the polycation/DNA/SPG ternary complex. Gel electrophoresis showed that presence of SPG influenced the migration pattern of polycation+DNA mixtures. With increasing the SPG ratio, the zeta potential (ζ) of the polycation+DNA+SPG mixture decreased drastically to reach almost ζ = 0 and the particle size distributions were altered due to the ternary complex formation. Confocal laser scanning microscopy revealed that the polycation/DNA/SPG ternary complexes showed high uptake efficiency when the complexes were exposed to macrophage-like cells (J774.A1). IL-12 secretion was enhanced when CpG-DNA was added as the ternary complex. These features can be ascribed to the fact that J774.A1 has a SPG recognition site called Dectin-1 on the cellular surface and the ternary complex can be ingested by this pathway..
183. K. Kaneko, K. Inoke, B. Freitag, A. B. Hungria, P. A. Midgley, T. W. Hansen, J. Zhang, S. Ohara and T. Adschiri, Structural and morphological characterization of cerium oxide nanocrystals prepared by hydrothermal synthesis, Nano Letters, Vol.7 No.2 (2007) pp.421-425, 2007.02, [URL].
184. Microstructures and Mechanical Properties of AZ61 Magnesium Alloy after Processing with High Pressure Torsion
Y. Harai K. Masaaki K. Kaneko and Z. Horita
Journal of Japan Institute of Metals
Vol.71 2(2007)pp.213-217..
185. K. Yamada, A. Ichinose, Y. Tomokiyo, Y. Shinkai, K. Matsumoto, Y. Yoshida, S. Horii, R. Kita, S. Toh, K. Kaneko, N. Mori and M. Mukaida, Moire Fringe Analysis of BaZrO3 Nano-Rods in ErBa2Cu3O7-x Films, Japanese Journal of Applied Physics, Vol.46 No.2 (2007) pp.708-711, 2007.02, [URL].
186. Y.-W. Jeong, K. Uezu, M. Kobayashi, S. Sakurai, H. Masunaga, K. Inoue, S. Sasaki, N. Shimada, Y. Takeda, K. Kaneko and K. Sakurai, Complex Made from Tetrasodium N N-Bis(carboxylatomethyl) Glutamate and Sodium Oleate that Forms a Highly Ordered Lamella in Gel Phase, Bulletin of the Chemical Society of Japan, Vol.80 No.2 (2007) pp.410-417, 2007.02, [URL].
187. Yeonhwan Jeong, Kazuya Uezu, Masataka Kobayashi, Shinichi Sakurai, Hiroyasu Masunaga, Katuaki Inoue, Sono Sasaki, Naohiko Shimada, Yoichi Takeda, Kenji Kaneko, Kazuo Sakurai, Complex made from tetrasodium N,N-bis(carboxylatomethyl) glutamate and sodium oleate that forms a highly ordered lamella in gel phase, Bulletin of the Chemical Society of Japan, 10.1246/bcsj.80.410, 80, 2, 410-417, 2007.02, When we mixed two transparent aqueous solutions of tetrasodium N,N-bis(carboxylatomethyl) glutamate (GLDA) and sodium oleate (OleNa), a white gel phase was formed when the total solute concentrations were higher than about 2.8 wt %, indicating that complexation between GLDA and OleNa caused the gelation. The appearance of the gel was completely opaque, the gel displayed thixotropy, and the gel state changed to the sol state upon heating. Optical microscopy showed that the gel consisted of very long fibers with diameters ranging from nanometers to micrometers. Transmission electron microscopy showed that the long fibers were made from many bundled, straight fibrils with a width of 200-1000 nm. The fibril consisted of lamellae parallel to the axial direction of the fibril. X-ray scattering confirmed the lamellar structure with a spacing of 4.5 nm, and the spacing was independent of the concentration and the molar ratio of GLDA and OleNa. The area of the lamellar first peak reached a maximum at the molar ratio of GLDA:OleNa = 4:1, i.e., this ratio is the stoichiometry of the GLDA/OleNa complex. This stoichiometric number was confirmed by high-performance liquid chromatography..
188. Yosuke Harai, Masaaki Kai, Kenji Kaneko, Zenji Horita, Microstructures and mechanical properties of AZ61 magnesium alloy after processing with high presser torsion, Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, 10.2320/jinstmet.71.213, 71, 2, 213-217, 2007.02, A magnesium alloy AZ61 was subjected to a process of severe plastic deformation through high pressure torsion (HPT) at room and elevated temperatures. For the HPT process, a pressure of 3 GPa was applied to the alloy with a disk-shaped sample having dimensions of 10 mm in diameter and 0.8 mm in thickness while the lower anvil was rotated with respect to the upper anvil with a rotation speed of 1 rpm for up to 7 turns. Microstructures were observed using optical microscopy and transmission electron microscopy. Hardness was measured across the diameter of the sample to examine any variation with respect to positions from the center of the disk under different HPT conditions. Tensile tests were carried out at 473 K with initial strain rates ranging from 3.3 × 10-4 s-1 to 3.3 × 10-2 s -1. Microstructure observations revealed that the average grain size was reduced to 0.52, 0.37, 0.23 and 0.22 μm after 1, 3, 5 and 7 turns, respectively, for HPT performed at 423 K, Superplasticity with an elongation to failure of 620% was attained for the sample processed after 5 turns at 423 K when the tensile specimen was deformed at 473 K with an initial strain rate of 3.3 × 10-3 s-1..
189. Kazuhiro Yamada, Ataru Ichinose, Yoshitsugu Tomokiyo, Yuki Shingai, Kaname Matsumoto, Yutaka Yoshida, Shigeru Horii, Ryusuke Kita, Shoichi Toh, Kenji Kaneko, Nobuyuki Mori, Masashi Mukaida, Moiré fringe analysis of BaZrO3 nanorods in ErBa 2Cu3O7-δ films, Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes, 10.1143/JJAP.46.708, 46, 2, 708-711, 2007.02, Microstructures of BaZrO3 (BZP) doped as artificial pinning centers in ErBa2Cu3O7-δ (ErBCO) films were studied by high-resolution transmission electron microscopy (HR-TEM). BZP-doped ErBCP films were grown by a pulsed laser deposition (PLD) method. In the HR-TEM observation, the presence of nanorods with 10nm average diameter was confirmed from Moiré fringe analysis. The lattice constant of nanorods in the ErBCP was measured using a selected area electron diffraction pattern (SAEDP) as 0.416 nm, which was in good agreement with the lattice constant of BZP, 0.419 nm, provided by X-ray diffraction data. Moiré fringes were observed in both cross-sectional-view and plan-view of the HR-TEM images. The distances of the Moiré fringes were 2.07, 3.22, and 3.05 nm, and which corresponded to the 200, 006, and 110 reflections of the ErBCP matrix and the 200, 002, and 110 reflections of nanorods, respectively. It is suggested that BZO disperses in ErBCO film as nanorods..
190. Kenji Kaneko, Koji Inoke, Bert Freitag, Ana B. Hungria, Paul A. Midgley, Thomas W. Hansen, Jing Zhang, Satoshi Ohara, Tadafumi Adschiri, Structural and morphological characterization of cerium oxide nanocrystals prepared by hydrothermal synthesis, Nano Letters, 10.1021/nl062677b, 7, 2, 421-425, 2007.02, Colloidal cerium oxide (CeO2) nanocrystals prepared by hydrothermal synthesis were characterized by high-resolution transmission electron microscopy (HRTEM) and three-dimensional electron tomography (3D-ET). HRTEM images of individual CeO2 nanocrystals were then simulated by Blochwave and multislice simulations to determine the atomic arrangement and terminating atoms. The edge length distributions were between 5.0 and 8.0 nm with an average edge length of 6.7 nm. The HRTEM images showed that the CeO 2 particles were slightly truncated revealing {220} facets. 3D-ET revealed that the CeO2 nanocrystals exposed predominantly {200} cubic facets. The nanocrystals were truncated at the corners exposing {111} octahedral facets and at the edges {220} dodecahedral facets. Furthermore, 3D-ET revealed the presence of some tetragonal-shaped CeO2 nanocrystals..
191. S. Tanemura, L. Miao, Y. Kajino, M. Tanemura, S. Toh, K. Kaneko, Y. Mori, Structural and optical characterization of semiconducting TiN nanoparticles thin film, Japanese Journal of Applied Physics, Vol.46 No.1 (2007) pp.356-361, 2007.01, [URL].
192. Influence of ECAP process on Magnetic Property of Cu-6.5mass%Co alloy containing Co precipitates, K.Suehiro, S. Nishimura, K. Kaneko, Z. Horita, Journal of IRICu, Vo.46 No.1 (2007) pp.172-176.
193. T. Kojima, R. Harada, T. Nakanishi, K. Kaneko, S. Fukuzumi, Porphyrin Nanotubes Based on Self-Assembly of Mo(V)-dodecaphenylporphyrin Complexes and Inclusion of Mo-oxo Clusters: Synthesis and Characterization by X-ray Crystallography and Transmission Electron Microscopy, Chemistry of Materials, Vol.19 No.1 (2007) pp.51-58, 2007.01, [URL].
194. Takahiko Kojima, Ryosuke Harada, Tatsuaki Nakanishi, Kenji Kaneko, Shunichi Fukuzumi, Porphyrin nanotubes based on self-assembly of Mo(V)-dodecaphenylporphyrin complexes and inclusion of Mo-oxo clusters
Synthesis and characterization by X-ray crystallography and transmission electron microscopy, Chemistry of Materials, 10.1021/cm062031k, 19, 1, 51-58, 2007.01, A saddle-distorted molybdenum(V)-dodecaphenylporphyrin (H2DPP) complex, [Mo(DPP)(O)(OMe)] (1), was converted to [Mo(DPP)(O)(H 2O)]+ (2) in the course of recrystallization from toluene with vapor diffusion of methanol. The complex 2 was organized via self-assembly to form a porphyrin nanotube having a diameter of 1 nm, concomitant with size-selective inclusion of three kinds of novel tetranuclear Mo(VI)-oxo clusters in the nanotube. This porphyrin nanotube exhibits amphiphilic characteristics, that is, a hydrophobic porphyrin surface and a hydrophilic inner-sphere made of aquo ligands to include ionic and hydrophilic entities. Each nanotube has no direct interaction; however, the toluene molecules of crystallization linked the nanotubes together with intermolecular π-π and CH/π interactions. Transmission electron microscopy measurements and energy-dispersive X-ray analysis revealed that the diameters of porphyrin nanotubes could be altered by the size of the Mo-oxo clusters included and also a porphyrin nanoring could be obtained. These results indicate that a variety of porphyrin nanotubular structures can be fabricated by using DPP complexes via cooperatively template-assisted self-assembly..
195. Sakae Tanemura, Lei Miao, Yoichi Kajino, Masaki Tanemura, Shoichi Toh, Kenji Kaneko, Yukimasa Mori, Structural and optical characterization of semiconducting TiN nanoparticles thin film, Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes, 10.1143/JJAP.46.356, 46, 1, 356-361, 2007.01, We have succeeded in fabricating a thin film consisting of semiconducing TiN nanoparticles soft-landed on a substrate at room temperature using N 2 reactive magnetron sputtering combined with a gas aggregation method. The total film thickness is about 1200nm. Under the optimized experimental parameters for controlling the growth of TiN particles, the average diameter of TiN nanoparticles is 2.54nm and their diameter distribution is from 1.1 to 3.8 nm. X-ray photoelectron spectroscopy (XPS) study reveals that the fabricated semiconducting TiN has N vacancies and/or defects as Ti xN1-x. The average lattice constant of the TiN particulates is estimated as 4.216 Å and contracted by 0.6% from that of bulk TiN, which is presumably caused by the vacancies and/or defects. Spectroscopic ellipsometry (SE) study revealed that the imaginary part of the dielectric constant of the present film shows typical semiconducting behavior and gives the optical band gap of the film as 3.65 eV in direct allowed optical transition mode..
196. Kenji Kaneko, Keisuke Sato, Zenji Horita, Koji Inoke, Characterization of precipitates by three-dimensional electron tomography, 6th Pacific Rim International Conference on Advanced Materials and Processing, PRICM 6 Selected, peer reviewed papers from The Sixth Pacific Rim International Conference on Advanced Materials and Processing, PRICM 6, 561-565, 2009-2012, 2007.01, Structures and morphologies of Ge precipitates in an Al-Ge alloy were characterized by a combination of transmission electron microscopy and three-dimensional electron tomography. Faceting of the precipitates was clearly seen using transmission electron microscopy and varieties of precipitate morphologies were identified by three-dimensional electron tomography..
197. Sudip Malik, Norifumi Fujita, Pritam Mukhopadhyay, Yuta Goto, Kenji Kaneko, Toshiji Ikeda, Seiji Shinkai, Creation of 1D [60]fullerene superstructures and its polymerization by γ-ray irradiation, Journal of Materials Chemistry, 10.1039/b701583f, 17, 23, 2454-2458, 2007.01, Conventional sublimable solid solvents such as naphthalene, ferrocene and camphor finely dissolve [60]fullerene (C60) in the solution state. After cooling to room temperature and removal of the solid solvents from the composites, C60 forms fibrous superstructures that are characterized by scanning electron microscopy. X-Ray powder diffraction study and ATR/IR analysis show that the C60 superstructures preserve the fcc lattice as in pristine C60. NMR together with elemental analysis reveals the presence of significantly less solvent in the superstructures. We have attempted to immobilize or polymerize the superstructures by a γ-ray irradiation technique that eventually leads to the formation of a rod-like fullerene polymer. HR-TEM and photoluminescence studies support the formation of the superstructures and the subsequent γ-ray induced polymerization of C 60, which will provide new avenues for the realistic application of these with unprecedented materials properties..
198. Ayumu Umemoto, Koichi Hayashi, Kyoko Hayano, Noritaka Saito, Kenji Kaneko, Kunihiko Nakashima, Effect of mo powder surface condition on fabrication of Mo-SiO2 functionally graded materials with slipcasting method, 2nd International Conference on Characterization and Control of Interfaces for High Quality Advanced Materials, and Joining Technology for New Metallic Glasses and Inorganic Materials Proceedings of the 2nd Int. Conf. Characterization and Control of Interfaces for High Quality Advanced Materials, and Joining Technology for New Metallic Glasses and Inorganic Materials, 198, 219-224, 2007.01, The conventional high intensity discharge lamps are made of Mo foil-sealing method, in which the Mo-metal of 30 μm thick is sandwiched by the fused silica envelope. The conventional high intensity discharge lamps therefore requires cooling system to reduce the thermal stress between Mo and fused silica during the switching operation and a long sealing zone is usually required to complete hermeticity, especially in high power devices, so that the production of compact high intensity discharge lamps has been a Herculean task. We show the invention of the new type of hermetically-sealed high intensity discharge lamps, made of Mo-SiO2 functionally graded material (FGM) as an electrode and a sealing component. In the case of high intensity discharge lamps with Mo-SiO2 FGM (FGM-Lamp), the thermal expansion coefficient between Mo and SiO2 is functionally graded so that it tolerates a large numbers of heating cycles, with no cooling system are required. Furthermore lamps survive without breakage. The W electrode is totally separated from the lamp envelope by the FGM, so that no leakage of the luminous elements or gases takes place, when a large gas pressure exists inside a lamp. In this paper, effects of Mo powder surface conditions on the fabrication of Mo-SiO 2 FGM have been investigated. Mo-SiO2 FGM with as-received Mo powder revealed that the Mo particles were homogenously distributed, which resulted in no microscopic compositional gradient. In contrast. Mo-SiO 2 FGM with pre-treated Mo powder provided a uniform gradient from the conductive part (Mo-rich phase) to the sealing part (amorphous silica)..
199. Michihiro Shirakawa, Norifumi Fujita, Takahiro Tani, Kenji Kaneko, Masayoshi Ojima, Akihiko Fujii, Masanori Ozaki, Seiji Shinkai, Organogels of 8-quinolinol/metal(II)-chelate derivatives that show electron- and light-emitting properties, Chemistry - A European Journal, 10.1002/chem.200601813, 13, 15, 4155-4162, 2007.01, 8-Quinolinol/copper(II)-, palladium(II)-, and platinum(II)-chelate-based organogelators (IM) and their nongelling reference compounds (2M) were synthesized. Complexes IM could gelate various organic solvents at very low concentrations. Electron microscope measurements gave visual images of well-developed fibrous structures characteristic of low-molecular-weight organogels. UV/Vis and FTIR spectroscopy revealed that the good gelation ability of IM arises from the π-π interactions of the chelate moieties and the hydrogen-bond interactions among the amide groups. Very interestingly, field emission performances of the nanofibers prepared from the IM gels are evidently different depending on the electronic states of the three kinds of central metals. In addition, the 1Pt gel shows unique thermo- and solvatochromism of visible and phosphorescent color in response to a sol-gel phase transition. Furthermore, the 1Pt gel possesses an attractive ability to inhibit dioxygen quenching of excited triplet states, which increases the phosphorescence quantum yield of this gel. This effect is attributed to the isolation effect of the phosphorescent chelate moiety from the dioxygen-containing solution phase..
200. Rie Wakabayashi, Kenji Kaneko, Masayuki Takeuchi, Seiji Shinkai, Toward the alignment of conjugated polymers into anisotropically-ordered structure, New Journal of Chemistry, 10.1039/b701068k, 31, 6, 790-799, 2007.01, Recently, oriented polymers and/or polymer nanostructures have attracted a large amount of attention for their potential applications as, for example, electric devices such as FETs, LEDs, photovoltaic cells, and so forth. Besides several methods for organizing conjugated polymers, we have recently reported a novel concept for the alignment of conjugated polymers through the action of supramolecular bundling molecules. We here introduce two different approaches for aligning conjugated polymers; one is to utilize a crosslinking molecule ('aligner'), and the other is to use a twining polymer ('twimer') for organizing conjugated polymers. Aligner binds and crosslinks conjugated polymers in a positive allosteric manner to form organized supramolecular assemblies in solution. The cast film from the solution resulted in a crystalline sheet with periodicities corresponding to the distance between polymers, confirmed by several microscopic studies. On the other hand, twimer helically twins around the conjugated polymers to form one-dimensional (1D) complex in solution and the complex self-assembles into two-dimensionally (2D) aligned structure in drying process. The resulting film of conjugated polymer-twimer composites gave also highly ordered, crystalline structure. The principal results obtained both in solution and solid states and their future perspectives are discussed here..
201. Kunihiro Ohashi, Takeshi Fujita, Kenji Kaneko, Zenji Horita, Terence G. Langdon, The aging characteristics of an Al-Ag alloy processed by equal-channel angular pressing, Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing, 10.1016/j.msea.2006.08.024, 437, 2, 240-247, 2006.11, An Al-10.8 wt.% Ag alloy was processed by equal-channel angular pressing (ECAP) and aged at temperatures of 373 or 473 K. Hardness measurements were taken after different aging times and the results show the hardness continuously decreases when aging at 473 K but increases to a peak hardness when aging at 373 K. For aging at 473 K, it is shown that metastable γ′-phase particles form within the grains and stable γ-phase particles form throughout the sample but these particles make no contribution to the hardness. By contrast, aging at 373 K leads to the formation of stable γ-phase particles on the grain boundaries and a fine dispersion of η-zones and plate-like γ′-phase particles within the grains: the increase in hardness is attributed to these finely-dispersed particles. Aging at 373 K for 100 h, corresponding to peak aging, gives an increase in the uniform elongation in tensile testing and the same high level of stress as in samples after ECAP processing..
202. Effect of Oxygen on Aluminum Corrosion in Pure Water
K. Ishii R. Ozaki K. Kaneko and M. Masuda
Journal of Japan Institute of Metals
Vol.70 No.10(2006)pp.845-848..
203. M. Miura, M. Mukaida, K. Matsumoto, Y. Yoshida, A. Ichinose, S. Horii, R. Kita, A. Saito, K. Kaneko, K. Yamada, N. Mori, Effects of BaZrO3 dispersion into EuBa2Cu3O7-d superconducting thin films, Physica C: Superconductivity and its applications, Vol.445-448 (2006) pp.845-848, 2006.10, [URL].
204. Z. Horita, K. Oh-ishi and K. Kaneko, Microstructure control using severe plastic deformation, Science and Technology of Advanced Materials, Vol.7 No.7 (2006) pp.649-654, 2006.10, [URL].
205. K. Kaneko, R. Nagayama, K. Inoke, E. Noguchi and Z. Horita, Application of three-dimensional electron tomography ・Two types of Si-phases in Al-Si alloy ・, Science and Technology of Advanced Materials, Vol.7 No.7 (2006) pp.726-731, 2006.10, [URL].
206. Kenji Kaneko, Ryo Nagayama, Koji Inoke, Etsuko Noguchi, Zenji Horita, Application of three-dimensional electron tomography using bright-field imaging-Two types of Si-phases in Al-Si alloy, Science and Technology of Advanced Materials, 10.1016/j.stam.2006.06.006, 7, 7, 726-731, 2006.10, When a dilute amount of Si is added to Al, it results in the precipitation of Si-phases, either planar- and/or rod-type, depending on the ageing conditions. Observation of these phases had been carried out by TEM two dimensionally so far; nevertheless information of the thickness as well as the distribution had been neglected in the past. In this paper, a combination of electron diffraction, high-resolution transmission electron microscopy, and three-dimensional electron tomography was applied to characterize the morphologies and the orientation relationship of the Si-phases in an Al-Si alloy..
207. Katsuya Ishii, Ryota Ozaki, Kenji Kaneko, Masataka Masuda, Effect of oxygen on aluminum corrosion in pure water, Nippon Kinzoku Gakkaishi/Journal of the Japan Institute of Metals, 10.2320/jinstmet.70.845, 70, 10, 845-848, 2006.10, When aluminum is immersed in pure water, hydrogen evolves at the cathode in pure water where there is no oxygen, although hydrogen dose not evolve in pure water with oxygen present. Based upon the fact, the effect of hydrogen evolved at the cathode on aluminum corrosion was investigated in relation to oxygen concentration in pure water in the present study. The length of incubation period, which is the time from the beginning of the corrosion test to a sharp increase in the corrosion amount, is almost constant regardless of the oxygen concentration. However, the corrosion period which begins right after the incubation period and continues until the saturation point is reached varies depending on the oxygen concentration. When the oxygen concentration is low, the amount of hydrogen at the cathode is large and small pits through the barrier layer spread rapidly over the entire surface, resulting in increase in the corrosion amount. From these results, it is thought that the hydrogen evolved by the cathode reaction greatly affects the deterioration of barrier layer and the aluminum corrosion..
208. M. Miura, Masashi Mukaida, K. Matsumoto, Y. Yoshida, A. Ichinose, S. Horii, R. Kita, A. Saito, Kenji Kaneko, K. Yamada, N. Mori, Effects of BaZrO3 dispersion into EuBa2Cu3O7-δ superconducting thin films, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2006.06.016, 445-448, 1-2, 845-848, 2006.10, Surface resistances (RS) have been measured for EuBa2Cu3O7-δ (EuBCO) films grown in an ozone atmosphere. We grew BaZrO3 dispersed EuBCO films with artificial pinning centers (APCs) in an ozone atmosphere. We have investigated the effects of BaZrO3 dispersion into EuBCO films. The EuBCO films were grown using a pulsed laser deposition (PLD) in an ozone atmosphere on (1 0 0) SrTiO3 substrates. We use a pure EuBCO target and an EuBCO + 1.0 wt% BaZrO3 target. By BaZrO3 dispersion into EuBCO films, the crystallinity of BaZrO3 dispersed EuBCO films was poorer than that of pure EuBCO films. BaZrO3 dispersion into EuBCO films did not improve their superconducting characteristics. Then we evaluated microstructure by using transmission electron microscopy (TEM). We observed nano-rods in BaZrO3 dispersed EuBCO films. However, we did not observe nano-rods in BaZrO3 dispersed EuBCO films grown in an oxygen atmosphere. The differences between an ozone and an oxygen atmosphere influence on nano-rod forming. We found that the nano-rod size is important and is strongly related to not only RE (RE: Rare Earth) ion radii but also growth conditions of films..
209. Zenji Horita, Keiichiro Oh-ishi, Kenji Kaneko, Microstructure control using severe plastic deformation, Science and Technology of Advanced Materials, 10.1016/j.stam.2006.05.011, 7, 7, 649-654, 2006.10, The process of severe plastic deformation (SPD) was applied to Al alloys in order to demonstrate that it is possible to control the morphology and distribution of second phase particles using SPD. Equal-channel angular pressing (ECAP) is used for the SPD process and transmission electron microscopy is used for the microstructural observations. It is shown that precipitate particles are severely deformed or fragmented by the shear strain introduced by the ECAP process. It is also shown that the particles may even be dissolved in the matrix when the strain becomes intense. However, the change in the particle size and morphology are different depending on the alloy system..
210. Yoichi Takeda, Naohiko Shimada, Kenji Kaneko, Kazuo Sakurai, Seiji Shinkai, Property of polysaccharide nano gel involves polyion complex consists of cationic polymer/ DNA, 2006.10, It is known to be hydrophobic as for the Polyion complex that consisits of DNA and the cation when it is equal compared with the cation/anion. On the other hand, when the DMSO solution of β glucan is dropped to water, the Nano gel that has the hydrophobic area internally is formed. We found that DNA and the cation complex be able to be involved in the Nano gel of Schizophyllan that one of β glucan for the first time in this research. Moreover, the application of CpG DNA delivery will be described..
211. K. Yamada, A. Ichinose, Y. Shingai, K. Matsumoto, Y. Yoshida, S. Horii, R. Kita, S. Toh, Kenji Kaneko, N. Mori, Masashi Mukaida, TEM observation of ErBa2Cu3O7-δ films with BaZrO3 artificial pinning centers, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2006.06.012, 445-448, 1-2, 660-664, 2006.10, Microstructure of ErBa2Cu3O7-δ films with BaZrO3 as artificial pinning centers has been studied toward power application of a high temperature superconductor. ErBa2Cu3O7-δ films containing 1.5 mass% BaZrO3 were grown by a pulsed laser deposition method. Microstructure of the ErBa2Cu3O7-δ film with BaZrO3 was investigated by transmission electron microscopy (TEM). In the cross-sectional TEM observation, the nano-rods grew up along near the c-axis of ErBa2Cu3O7-δ film were observed. Width of the nano-rods was about 10 nm. We found twins with the averaged width of about 70 nm. The moiré fringes were also observed. In the EDS mapping analysis, zirconium was not detected clearly from the present TEM specimen. Space of the moiré fringes is about 1.9 nm. The lattice constant of a material in the ErBa2Cu3O7-δ film measured from the space of the moiré fringes is calculated to be 0.423 nm which coincides with the lattice constant of BaZrO3 (0.419 nm). Also, the lattice constant measured from the SADP is very close to the value of the BaZrO3. It is suggested that BaZrO3 disperses in ErBa2Cu3O7-δ film as the nano-rods..
212. Y. Hayashi, T. Tokunaga, K. Kaneko, S. J. Henley, V. Stolojan, J. D. Carey and S. R. P. Silva, Microstructure analyses of metal-filled carbon nanotubes synthesized by microwave plasma-enhanced chemical vapor deposition, IEEE Transactions on Nanotechnology, Vol.5 No.5 (2006) pp.485-490, 2006.09.
213. Yasuhiko Hayashi, Tomoharu Tokunaga, Kenji Kaneko, Simon J. Henley, Vlad Stolojan, J. David Carey, S. R P Silva, Microstructure analyses of metal-filled carbon nanotubes synthesized by microwave plasma-enhanced chemical vapor deposition, IEEE Transactions on Nanotechnology, 10.1109/TNANO.2006.880456, 5, 5, 485-490, 2006.09, Pd/Co-based metal-filled carbon nanotubes (MF-CNTs) were synthesized by a microwave plasma-enhanced chemical vapor deposition method using a bias-enhanced growth technique. Pd/Co-based MF-CNTs were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) electron energy loss spectroscopy (EELS), and Raman spectroscopy. MF-CNTs were well-aligned and uniform in size on a Si substrate. Both multiwall nanotube carbon nanotubes (CNTs) and herringbone (or stacked cups structure) structures were observed. High-resolution TEM revealed that MF-CNTs were composed of highly ordered graphite layers, and the elemental maps of EELS indicate that both Co and Pd metals are present inside the nanotubes. TEM results clearly showed that both Pd and Co metals were successfully encapsulated into the CNTs. We observed a low value for the Raman intensity ratio between D (1355 cm-1) and G (1590 cm-1) bands with no shift of the G-peak position and no broadening of the G-peak, indicative of high-quality Pd/Co-based MF-CNTs. Based on TEM characterization, we propose a description for the encapsulating mechanisms..
214. M. Takeuchi, C. Fujikoshi, Y. Kubo, K. Kaneko and S. Shinkai, Conjugated Polymers Complexed with Helical Porphyrin Oligomers Create Micron-Sized Ordered Structures, Angewandte Chemie International Edition, Vol.45 No.33 (2006) pp.5494-5499, 2006.08, [URL].
215. Masayuki Takeuchi, Chiaki Fujikoshi, Yohei Kubo, Kenji Kaneko, Seiji Shinkai, Conjugated polymers complexed with helical porphyrin oligomers create micron-sized ordered structures, Angewandte Chemie - International Edition, 10.1002/anie.200601493, 45, 33, 5494-5499, 2006.08, (Figure Presented) Straight curls: Conjugated polymers are aligned through the use of twining porphyrin oligomers (twimers), which act as helical "hosts" that twine around and are included within a single conjugated polymer. The resulting composites aggregate into relatively large 2D structures in the solid state and exhibit well-oriented periodic striping..
216. A. Umemoto, K. Hayashi, K. Nakashima, N. Saito, K. Kaneko and K. Ogi, Mo-SiO2 Functionally Graded Materials for High Intensity Discharge Lamps, Developments and Application of Advanced Engineering Ceramics and Composites: Ceramic Transactions, Vol.192 (2006) pp.53-58, 2006.07.
217. R. Wakabayashi, Y. Kubo, K. Kaneko, M. Takeuchi and S. Shinkai, Olefin Metathesis of the Aligned Assemblies of Conjugated Polymers Constructed through Supramolecular Bundling, Journal of American Chemical Society, Vol.128 No.27 (2006) pp.8744-8745, 2006.07, [URL].
218. S. Imagawa, K. Inoke, K. Kaneko, M. Hideki, K. Nakagawa, S. Takenaka and M. Kishida, Synthesis and Structural Characterization of Hollow Hexagonal Cylinder Co-SiO2 Composites Prepared in a Micelle Solution, Chemistry Letters, Vol.35 (2006) pp.816-817, 2006.07, [URL].
219. Rie Wakabayashi, Yohei Kubo, Kenji Kaneko, Masayuki Takeuchi, Seiji Shinkai, Olefin metathesis of the aligned assemblies of conjugated polymers constructed through supramolecular bundling, Journal of the American Chemical Society, 10.1021/ja063040x, 128, 27, 8744-8745, 2006.07, The ordered structures constructed from an aligner molecule 1o and conjugated polymers (CPs) were efficiently converted into the poly-pseudo-rotaxane structures by the template-assisted ring-closing olefin metathesis (RCM) of olefinic groups at the peripheral positions of 1o. Moreover, the poly-pseudo-rotaxane structures permitted the separation of the crystalline ordered assemblies of CP by size exclusion chromatography and the preservation of the sheet morphologies after the treatment with trifluoroacetic acid. The morphologies and the periodicities of assemblies were also maintained after the retrieving treatments..
220. Satoshi Imagawa, Koji Inoke, Kenji Kaneko, Hideki Matsune, Keizo Nakagawa, Sakae Takenaka, Masahiro Kishida, Synthesis and structural characterization of hollow hexagonal cylinder Co-SiO 2 composites prepared in a micelle solution, Chemistry Letters, 10.1246/cl.2006.816, 35, 7, 816-817, 2006.07, Novel submicron scale composites with hollow hexagonal cylinder structures were prepared by hydrolysis of tetraethyl orthosilicate in a micelle solution composed of polyoxyethylene (n = 15) cetyl ether/cyclohexane/water containing Co-N 2H 4 compound nanoparticles..
221. K. Inoke, K. Kaneko, M. Weyland, P. A. Midgley, K. Higashida and Z. Horita, Severe local strain and the plastic deformation of Guinier-Preston zones in the Al-Ag system revealed by 3D electron tomography, Acta Materialia, Vol.54, No.11, (2006) pp.2957-2963, 2006.06, [URL].
222. Koji Inoke, Kenji Kaneko, Matthew Weyland, Paul A. Midgley, Kenji Higashida, Zenji Horita, Severe local strain and the plastic deformation of Guinier-Preston zones in the Al-Ag system revealed by three-dimensional electron tomography, Acta Materialia, 10.1016/j.actamat.2006.02.029, 54, 11, 2957-2963, 2006.06, A severe bulk strain, γ ∼ 1, intentionally introduced into an Al-Ag specimen by the equal-channel angular pressing process caused nearly spherical Guinier-Preston (GP) zones and {1 1 1} planar γ′ phases to be sheared by dislocation motion. Although distortion of GP zones in the Al-Ag system was observed by Nicholson and Nutting in 1961, the three-dimensional morphology or the amount of strain of the deformed GP zones has not been studied to date. The presence of fine-scale distorted (ellipsoidal) GP zones parallel to the {1 1 1} slip planes is revealed using three-dimensional atomic number, Z-contrast electron tomography. The GP zones lie within localized shear bands, which result from the introduction of the severe strain. The local shear strain, measured at the nanoscale, within the shear band was determined to be 1.83 ± 0.272, a value considerably more than previously expected..
223. Y. Hayashi, T. Tokunaga, K. Kaneko and Z. Horita, Characterization of transport properties of multiwalled carbon nanotube networks by microwave plasma chemical vapor deposition, Diamond and Related Materials, Vol.15 (2006) pp.1138-1142, 2006.04, [URL].
224. Yasuhiko Hayashi, T. Tokunaga, Kenji Kaneko, Zenji Horita, Characterization of transport properties of multiwalled carbon nanotube networks by microwave plasma chemical vapor deposition, Diamond and Related Materials, 10.1016/j.diamond.2006.01.006, 15, 4-8, 1138-1142, 2006.04, We report the synthesis of multiwalled carbon nanotubes (MWCNTs) and the characterization of temperature-dependent electrical transport properties of MWCNT networks by using a two-point configuration without the lithographical technique. MWCNTs were grown by microwave plasma chemical vapor deposition with the bias enhanced growth technique. The Raman intensity ratio between the D- (∼1360 cm- 1) and G- (∼1590 cm- 1) peaks (ID / IG) as well as the full width at half maximum of the G-peak decreased from 1.03 to 0.03 and 18 to 13 cm- 1, respectively, with the increase in the oxidative purification time. This indicates that the crystallinity of graphite sheets is improved by the oxidative purification process and burn-off of the defects in MWCNT networks. The metal electrodes were attached on both the top and the bottom of the insulating thin films, and the as-grown and oxidative-purified MWCNT networks were connected between the electrodes for I-V measurements at various temperatures. At room temperature, the conductance for the MWNT networks at around zero bias was 0.65 G0 (G0: fundamental conductance unit), which was less than the value of 1 G0 for metallic MWCNTs. Further, the conductance increased linearly with the bias voltage until it attained its peak. In the 190-390 K range, the temperature characteristic of the I-V shows that the electron transport of the as-grown MWCNT networks was activated by a lower activation energy than that in oxidative-purified MWCNT networks..
225. A. Umemoto, K. Hayashi, K. Nakashima, N. Saito, K. Kaneko and K. Ogi, High Intensity Discharge Lamp with Mo-SiO2 Functionally Graded Material, Journal of the American Ceramics Society, Vol.89 No.3 (2006) pp.1133-1135, 2006.03, [URL].
226. H. Abe, K. Murata, T. Fukui, W.-J. Moon, K. Kaneko and M. Naito, Microstructural control of Ni-YSZ cermet anode for planar thin-film SOFCs, Fuel Cells Bulletin, No.3 (2006) pp.12-15, 2006.03.
227. Ayumu Umemoto, Koichi Hayashi, Kunihiko Nakashima, Noritaka Saito, Kenji Kaneko, Keisaku Ogi, High-intensity discharge lamp with Mo-SiO2 functionally graded material, Journal of the American Ceramic Society, 10.1111/j.1551-2916.2005.00835.x, 89, 3, 1133-1135, 2006.03, We show the invention of the new type of hermetically sealed high-intensity discharge lamps, made of Mo-SiO2 functionally graded material (FGM) as an electrode and a sealing component. In the case of high-intensity discharge lamps with Mo-SiO2 FGM (FGM lamp), the thermal expansion coefficient between Mo and SiO2 is functionally graded so that it tolerates a large number of heating cycles, with no cooling system required. Furthermore, lamps survive without breakage. The W electrode is totally separated from the lamp envelope by the FGM, so that no leakage of the luminous elements or gases takes place, when a large gas pressure exists inside a lamp..
228. H. Abe, K. Murata, T. Fukui, W.-J. Moon, K. Kaneko, M. Naito, Microstructural control of Ni-YSZ cermet anode for planer thin-film solid oxide fuel cells, Thin Solid Film, Vol.496 No.1 (2006) pp.49-52, 2006.02, [URL].
229. T. Fujita, S. Nishimura, T. Fujinami, K. Kaneko, Z. Horita, D. J. Smith, Application of equal-channel angular pressing to Cu-Co alloy with ferromagnetic precipitates, Material Science Engineering A, Vol.417 No.1-2 (2006) pp.149-157, 2006.02, [URL].
230. Aluminum corrosion in deaerated pure water
K. Ishii R. Ozaki K. Kaneko and M. Masuda
Journal of Japan Institute of Light Metals
Vol.56 No.2(2006)pp.82-87..
231. Yohei Kubo, Yumiko Kitada, Rie Wakabayashi, Takanori Kishida, Masatsugu Ayabe, Kenji Kaneko, Masayuki Takeuchi, Seiji Shinkai, A supramolecular bundling approach toward the alignment of conjugated polymers, Angewandte Chemie - International Edition, 10.1002/anie.200503128, 45, 10, 1548-1553, 2006.02, (Figure Presented) All line up together! A new concept for the alignment and assembly of conjugated polymers through the action of supramolecular bundling ("aligner") molecules is inspired by actin-filament bundling proteins. The approach provides a general means of preparing complex, ordered assemblies of conjugated polymers..
232. Katsuya Ishii, Ryota Ozaki, Kenji Kaneko, Masataka Masuda, Aluminum corrosion in deaerated pure water, Keikinzoku/Journal of Japan Institute of Light Metals, 10.2464/jilm.56.82, 56, 2, 82-87, 2006.02, The Amount of aluminum corrosion was critically measured in deoxidized pure water. It was indirectly calculated from the pressure of the hydrogen gas produced by the cathodic reaction. The accuracy of this device reached as high as 0.1 mg/m 2. The corrosion rate of A1N99 (99.99% aluminum) was then examined and compared with the images taken by both scanning electron microscope (SEM) and transmission electron microscope (TEM). In particular, images of the surface were taken by SEM and that of the cross section by TEM. From these comparisons, a new corrosion mechanism was proposed; 1) aluminum corrosion starts by the formation of small pits with a diameter of about 0.1 μm, 2) the number of these small pits increases and spreads over the entire surface. In addition, there is a time-lag between the increase of hydrogen gas pressure and the formation of corrosion products on the surface. The most likely reason for this time lag is that the Al ions require a long period of time to form stable oxide films..
233. Takeshi Fujita, Shunichi Nishimura, Takayoshi Fujinami, Kenji Kaneko, Zenji Horita, David J. Smith, Application of equal-channel angular pressing to Cu-Co alloy with ferromagnetic precipitates, Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing, 10.1016/j.msea.2005.11.008, 417, 1-2, 149-157, 2006.02, Experiments were conducted to evaluate the influence of equal-channel angular pressing (ECAP) on the magnetic properties of a Cu-1.8 wt.% Co alloy containing 0.2 wt.% Cr which forms ferromagnetic Co-rich precipitates in the Cu matrix after aging treatment. Coherent face-centered-cubic precipitates were formed by isothermal aging at 873 and 1073 K for 259 ks. The two different aging temperatures gave precipitates of different sizes, which were expected to show either single-domain or multidomain structure. In the case of small precipitates, one pass of ECAP was effective to improve coercivity, but further pressings tended to decrease coercivity and saturation magnetization due to random orientation and dissolution of the precipitates. In the case of large precipitates, shape change to increase coercivity is difficult. Saturation magnetization was increased by the demagnetizing effect of the precipitates. Electron holography provided the quantitative magnetization measurements for rounded cubic and elongated Co precipitates, indicating the increased in-plane magnetization of the elongated precipitate due to the demagnetizing effect as a result of deformation..
234. H. Abe, K. Murata, T. Fukui, W. J. Moon, Kenji Kaneko, M. Naito, Microstructural control of Ni-YSZ cermet anode for planer thin-film solid oxide fuel cells, Thin Solid Films, 10.1016/j.tsf.2005.08.191, 496, 1, 49-52, 2006.02, Ni-Y2O3-stabilized ZrO2 (Ni-YSZ) cermet anode was fabricated for solid oxide fuel cells (SOFCs) by conventional ceramic processing using NiO-YSZ composite particles. Microstructures of the anode were carefully characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The Ni-YSZ cermet anode was consisting of fine YSZ connections, as the conducting pass of oxygen ions, on the surface of Ni network, as that of electrons, with continuous pore structure and as that of gaseous species. No amorphous phases were present at the interface between Ni and YSZ, and there was an orientation relationship between Ni and YSZ grains, (111)Ni//(111)YSZ. The cermet anode showed a high electrical performance at 800 °C. These results indicated that the electrochemical activity of the Ni-YSZ cermet anode was enhanced with the present microstructure..
235. M. Takeuchi, C. Fujikoshi, Y. Kubo, K. Kaneko, S. Shinkai, Sequential organization by a supramolecular twining approach toward the alignment of conjugated polymers, Polymer Preprints Japan, Vol.55 No.1 (2006) pp.423-424, 2006.01.
236. M. Numata, S. Haraguchi, T. Fujisawa, K. Kaneko, K. Sakurai, S. Shinkai, Creation of novel nanomaterials utilizing biomaterials based on natural polysaccharide-conjugated polymer complex, Polymer Preprints Japan, Vol.55 No.1 (2006) pp.267-268, 2006.01.
237. A. Ikeda, S. Ito, J.-I. Kikuchi, K. Kaneko, M. Numata, K. Sakurai, S. Shinkai, Solubilization of C60 by using biopolymers, Polymer Preprints Japan, Vol.55 No.1 (2006) pp.1888-1889, 2006.01.
238. Y. Takeda, N. Shimada, K. Kaneko, K. Sakurai, S. Shinkai, Property of polysaccharide nano gel involves polyion complex consists of cationic polymer/ DNA, Polymer Preprints Japan, Vol.55 No.1 (2006) pp.1858-1859, 2006.01.
239. K. Nakamura, K. Neishi, K. Kaneko, M. Nakagaki, Z. Horita, Continuous Grain Refinement Using Severe Torsion Straining Process, Material Science Forum, Vol.503-504 (2006) pp.385-390, 2006.01.
240. Y. Kawasaki, K. Neishi, Y. Miyahara, K. Nakamura, K. Kaneko, M. Nakagaki, Z. Horita, Application of Severe Torsion Straining Process for Grain Refinement of Steel, Material Science Forum, Vol.503-504 (2006) pp.943-948, 2006.01.
241. Y. Miyahara, N. Emi, K. Neishi, K. Nakamura, K. Kaneko, M. Nakagaki, Z. Horita, Microstructures and Mechanical Properties of Mg alloy after Severe Torsion Straining Process, Material Science Forum, Vol.503-504 (2006) pp.949-954, 2006.01.
242. K. Neishi, A. Higashino, Y. Miyahara, K. Nakamura, K. Kaneko, M. Nakagaki, Z. Horita, Grain Refinement of Commercial Al-Mg alloy Using Severe Torsion Straining Process, Material Science Forum, Vol.503-504 (2006) pp.955-960, 2006.01.
243. H. Takahashi, Y. Niidome, T. Niidome, K. Kaneko, H. Kawasaki and S. Yamada, Modification of Gold Nanorods Using Phosphatidylcholine to Reduce Cytotoxicity, Langmuir, Vol.22 No.1 (2006) pp.2-5, 2006.01, [URL].
244. L. Miao, T. Jiang, S. Tanemura, M. Tanemura, M. Mori, S. Toh, K. Kaneko, Photochromic Ag-TiO2 thin films by dual-target hellicon magnetron sputtering, Advance Materials Research, Vol.11-12 (2006) pp.167-170, 2006.01.
245. Hironobu Takahashi, Yasuro Niidome, Takuro Niidome, Kenji Kaneko, Hideya Kawasaki, Sunao Yamada, Modification of gold nanorods using phosphatidylcholine to reduce cytotoxicity, Langmuir, 10.1021/la0520029, 22, 1, 2-5, 2006.01, Hexadecyltrimethylammonium bromide (CTAB), which is necessary for the preparation of gold nanorods (NRs), was extracted from a NR solution into a chloroform phase containing phosphatidylcholine (PC). After three extractions, the zeta potential of the NRs remained positive, but its magnitude decreased from+67 ±1 to+15± 1 mV. Transmission electron microscopy and energy-dispersive X-ray analysis indicated that the NRs were passivated with PC. The PC layer on the NR surface contributed to the prevention of NR aggregation. The PC-passivated NRs showed low cytotoxicity in comparison with twice-centrifuged NRs. It was shown that a negligible amount of CTAB was dispersed in the NR solution after the extraction. The extraction using a chloroform phase containing PC was found to be a convenient way of replacing the CTAB with alternative capping agents such as PC. This is a key technique for preparing functional NRs that can have practical applications..
246. Yoshiyasu Kawasaki, Koji Neishi, Yuichi Miyahara, Katsuaki Nakamura, Kenji Kaneko, Michihiko Nakagaki, Zenji Horita, Application of severe torsion straining process for grain refinement of steel, 3rd International Conference on Nanomaterials by Severe Plastics Deformation, NanoSPD3 Nanomaterials by Severe Plastic Deformation, NanoSPD3 - Proceedings of the 3rd International Conference on Nanomaterials by Severe Plastics Deformation, 503-504, 943-948, 2006.01, Severe torsion straining process (STSP) is a useful technique for grain refinement of metallic materials. With this process, a local heated zone is produced in a rod and one side of the rod is rotated with respect to the other so that torsion strain is introduced into the local heated zone. Severe straining is then achieved continuously throughout the rod by simultaneous rotation and longitudinal movement of the rod. Thus, the STSP is a continuous process and a die-less process for grain refinement. It is suggested that the STSP provide potential for commercialization. In this study, S45C steel rods with 12 mm in diameter were subjected to STSP. This process was conducted at a temperature of 923 K (650°C) with various ratios of rotation to longitudinal movement of a rod. Local heating was made using an induction coil and both sides of the local heated zone were cooled by water spray. Microscopy observation revealed that the initial grain size of ∼15 μm was reduced to ∼2 μm using the STSP..
247. Katsuaki Nakamura, Koji Neishi, Kenji Kaneko, Michihiko Nakagaki, Zenji Horita, Continuous grain refinement using severe torsion straining process, 3rd International Conference on Nanomaterials by Severe Plastics Deformation, NanoSPD3 Nanomaterials by Severe Plastic Deformation, NanoSPD3 - Proceedings of the 3rd International Conference on Nanomaterials by Severe Plastics Deformation, 503-504, 385-390, 2006.01, This study presents a new rapid continuous process for grain refinement in metallic materials through severe plastic deformation (SPD). The new process, designated in this study the severe torsion straining process (STSP), is applicable to a wide range of alloys based on aluminum, magnesium and copper including carbon steel. This process consists of producing a local heated zone in a rod and cooling both sides of the heated zone by spray water while rotating one end with the other. Thus, torsion strain is introduced in the local heated zone. The STSP can be continuous because the straining is achieved while the rod is shifted along the longitudinal axis of die rod. Furthermore, the process requires no die, suggesting a potential for commercialization of grain refinement through SPD. In this study, STSP was applied to an Al-Mg alloy and a Mg-Al-Zn alloy. It is shown that STSP is effective for both alloys so that the grain size is reduced to ∼1.5 μm for the Al alloy and ∼0.9 μm for the Mg alloy. Tensile testing showed that the strength is increased with a minimal decrease in uniform elongation. There is a critical ratio between rotation speed and moving speed, which defines the feasibility of STSP operation without breaking the rod. The grain size tends to be lowered as the ratio is close to the critical value..
248. Munenori Numata, Shunichi Haraguchi, Tomohisa Fujisawa, Kenji Kaneko, Kazuo Sakurai, Seiji Shinkai, Creation of novel nanomaterials utilizing biomaterials based on natural polysaccharide-conjugated polymer complex, 55th SPSJ Annual Meeting Polymer Preprints, Japan - 55th SPSJ Annual Meeting, 55, 267, 2006.01, It is already known that β-1,3-glucans form a hydrophobic cavity within the helical superstructure, which is surrounded by hydrophilic side-glucoses or primary OH groups. This unique core-shell structure resembles that of cyclodextrins, which are well-established hosts for C60. Therefore, the fact encouraged us to pursue the possibility that β-1,3-glucans could act as a novel one-dimensional host for single-walled carbon nanotubes (SWNTs). As expected, β-1,3-glucans can interact with SWNTs to produce unique nanocomposites, in which SWNTs are entrapped within a one-dimensional hollow constructed by the helical superstructure of β-1,3-glucans. Moreover, various conductive polymers are also entrapped within the one-dimensional hollow to be arranged into the one-dimensional array. Since the surface is covered with β-1,3-glucans, the complex has potential to be bionanomaterials, where β-1,3-glucans act as an interface between the conjugated polymer and biologically important molecules. We tested this idea utilizing schizophyllan/conjugated polymer complex..
249. Koji Neishi, Akihiko Higashino, Yuichi Miyahara, Katsuaki Nakamura, Kenji Kaneko, Michihiko Nakagaki, Zenji Horita, Grain refinement of commercial Al-Mg alloy using severe torsion straining process, 3rd International Conference on Nanomaterials by Severe Plastics Deformation, NanoSPD3 Nanomaterials by Severe Plastic Deformation, NanoSPD3 - Proceedings of the 3rd International Conference on Nanomaterials by Severe Plastics Deformation, 503-504, 955-960, 2006.01, Severe plastic deformation (SPD) makes it possible to refine grain size in many metallic materials. Recently, we have developed a new SPD process designated the severe torsion straining process (STSP). This process requires no die but one side of a rod is rotated with respect to the other while producing a local heated zone in the rod and cooling both sides of the heated zone. Torsion strain is then introduced in the local heated zone. The STSP can be a continuous process because the rod is moved in the longitudinal direction while introducing torsion strain through the rotation. For grain refinement using the STSP, various factors may affect, which are the rotation speed, moving speed, straining temperature, cooling rate and diameter of the rod. In this study, the STSP is applied to grain refinement of an A5056 Al-Mg commercial alloy and the factors affecting the grain refinement are optimized. STSP was conducted at a temperature in the range from 573K to 723K. Microstracture was observed by optical microscopy, scanning electron microscopy with an orientation imaging system, and transmission electron microscopy. Microscopy observations revealed that the grain size was reduced to ∼0.9 um, when STSP was conducted at 573K with a rotation speed of 10 rpm and moving speed of 50 mm/min. There is a critical ratio of rotation speed to moving speed above which the rod breaks. The grain size tends to be finer as the straining temperature is lower, the cooling rate is faster and the ratio of rotation speed to moving speed is closer to the critical value..
250. Y. Hayashi, T. Tokunaga, Kenji Kaneko, S. J. Henley, V. Stolojan, J. D. Carey, S. R P Silva, Microstructure analyses of metal-filled carbon nanotubes synthesized by microwave plasma-enhanced chemical vapour deposition, 2006 IEEE Conference on Emerging Technologies - Nanoelectronics NanoSingapore 2006: IEEE Conference on Emerging Technologies - Nanoelectronics - Proceedings, 10.1109/NANOEL.2006.1609696, 2006, 93-98, 2006.01, Pd/Co-based metal-filled carbon nanotubes (MF-CNTs) were synthesized by a microwave plasma-enhanced chemical vapour deposition method using a bias-enhanced growth technique. Pd/Co-based MF-CNTs were analyzed by scanning electron microscopy (SEM), transmission electron microscopy (TEM) electron energy loss spectroscopy (EELS), and Raman spectroscopy. MF-CNTs were well-aligned and uniform in size on a Si substrate. Both multiwall nanotube carbon nanotubes (CNTs) and herringbone (or stacked cups structure) structures were observed. High-resolution TEM revealed that MF-CNTs were composed of highly ordered graphite layers, and the elemental maps of EELS indicate that both Co and Pd metals are present inside the nanotubes. TEM results clearly showed that both Pd and Co metals were successfully encapsulated into the CNTs.. We observed a low value for the Raman intensity ratio between D (1355 cm-1) and G (1590 cm-1) bands with no shift of the G-peak position and no broadening of the G-peak, indicative of high quality Pd/Co-based MF-CNTs. Based on TEM characterization, we propose a description for the encapsulating mechanisms..
251. Yuichi Miyahara, Naoki Emi, Koji Neishi, Katsuaki Nakamura, Kenji Kaneko, Michihiko Nakagaki, Zenji Horita, Microstructures and mechanical properties of Mg alloy after severe torsion straining process, 3rd International Conference on Nanomaterials by Severe Plastics Deformation, NanoSPD3 Nanomaterials by Severe Plastic Deformation, NanoSPD3 - Proceedings of the 3rd International Conference on Nanomaterials by Severe Plastics Deformation, 503-504, 949-954, 2006.01, Grain refinement is attempted using severe plastic deformation (SPD) through the severe torsion straining process (STSP) which we have developed recently. The STSP is a continuous process for grain refinement without requirement of any die. In this study, an AZ61 Mg alloy was subjected to STSP at a temperature of 573 K with a rotation speed of 10 rpm and a moving speed of 200 mm/min. With this process, an initial grain size of ∼20 μm was reduced to ∼2∼3 μm. Room temperature compression tests revealed that there were no cracks after 15% of compression for the STSP sample whereas fracture occurred for a conventionally extruded sample. For compression tests at 473 K, no cracks occurred in the STSP samples after 80% compression but compression was feasible without cracking only up to 20% for an extruded sample. It is shown that the STSP can be useful for grain refinement and ductility improvement of the AZ61 Mg alloy..
252. Ayumu Umemoto, Koichi Hayashi, Kunihiko Nakashima, Noritaka Saito, Kenji Kaneko, Keisaku Ogi, Mo-SiO2 functionally graded materials for high intensity discharge lamp, 6th Pacific Rim Conference on Ceramic and Glass Technology, PacRim6 Developments and Applications of Advanced Engineering Ceramics and Composites - Proceedings of the 6th Pacific Rim Conference on Ceramic and Glass Technology, PacRim6, 192, 53-58, 2006.01, The conventional high intensity discharge lamps are made of Mo foil-sealing method, in which the Mo-metal of 30 μm thick is sandwiched by the fused silica envelope. The conventional high intensity discharge lamps therefore requires cooling system to reduce the thermal stress between Mo and fused silica during the switching operation and a lung sealing zone is usually required to complete hermeticity, especially in high power devices, so that the production of compact high intensity discharge lamps has been a Herculean task, Here, we show the invention of the new type of hermetically-sealed high intensity discharge lamps, made of Mo-SiO2 functionally graded material (FGM) as an electrode and a sealing component. In the case of high intensity discharge lamps with Mo-SiO2 FGM (FGM-Lanip), the thermal expansion coefficient between Mo and SiO2 is functionally graded so that it tolerates a large number of heating cycles, with no cooling system are required, Furthermore lamps survive without breakage of lamp takes place, The W electrode is totally separated from the lamp envelope by the FGM, so that no leakage of the luminous elements or gases takes place, when a large gas pressure exists inside a lamp..
253. Takahiro Kaseyamaj, Yohei Kubo, Kenji Kaneko, Masayuki Takeuchi, Seiji Shinkai, Nanoscale alignment of conjugated polymers by supramolecular approach(2), 55th Society of Polymer Science Japan Symposium on Macromolecules 55th SPSJ Symposium on Macromolecules, 55, 2934, 2006.01, We designed and synthesized a compound 1 that can align conjugated polymers. This compound has palladium complexes as molecular recognition units and can align polyanilines. The morphologies of the supramolecular assemblies consisting of this compound and polyaniline were monitored by UV-vis spectroscopy and TEM..
254. Shinji Takebsyashi, Yohei Kubo, Kenji Kaneko, Masayuki Takeuchi, Seiji Shinkai, Nanoscale alignment of conjugated polymers by a supramolecular approach, 55th Society of Polymer Science Japan Symposium on Macromolecules 55th SPSJ Symposium on Macromolecules, 55, 5239-5240, 2006.01, Exploring new methods for alignment of conjugated polymers is of importance for the production of materials having optimized properties. In these days, several methods for alignment of conjugated polymers have been reported by many research groups. We have recently proposed a new concept for alignment of conjugated polymers where the porphyrinatozinc tetramer was designed and utilized as an Aligner; the molecule binds amino functionalized cojugated polymers (CP1) to align them into the two-dimensional super structures. We here report an attempt on three-dimensional alignment of conjugated polymers by a poly-Aligner..
255. Koji Inoke, Kenji Kaneko, Zenji Horita, Observation of morphology for precipitates in aluminum alloys by electron tomography, Keikinzoku/Journal of Japan Institute of Light Metals, 10.2464/jilm.56.639, 56, 11, 639-643, 2006.01.
256. L. Miao, T. Jiang, S. Tanemura, M. Tanemura, M. Mori, S. Toh, Kenji Kaneko, Photochromic Ag-TiO2 thin films fabricated by dual-target helicon magnetron sputtering, AICAM 2005 - Asian International Conference on Advanced Materials AICAM 2005 - Proceedings of the Asian International Conference on Advanced Materials, 11-12, 167-170, 2006.01, Photochromic material Ag-TiO2 thin films are fabricated on quartz substrate by dual -target helicon magnetron sputtering. The phototchromic behavior is investigated for the sample loaded with 90% Ag. Spheres, ellipsoids and polyhedra shape of Ag particles with wide range size (5∼100 nm) are dispersed in the TiO2 amorphous matrix observed by transmission electron microscopy. The spectral hole burned by the irradiation of laser at the wavelength 532 nm can be explained by a particle-plasmon-assisted electron transfer from Ag nanoparticles to TiO2 and subsequent trapping by adsorbed molecular oxygen. Moreover, the mechanism of the slow recovery after photochromism is suggested as a slow thermal release of electrons from oxygen trapping centers and subsequent capture into the Ag nanoparticles..
257. Masayuki Takeuchi, Chiaki Fujikoshi, Yohei Kubo, Kenji Kaneko, Seiji Shinkai, Sequential organization by a supramolecular twining approach toward the alignment of conjugated polymers, 55th SPSJ Annual Meeting Polymer Preprints, Japan - 55th SPSJ Annual Meeting, 55, 423, 2006.01, Here we report that porphyrin polymers (Twining polymer; Twimer) possessing conjugated polymer binding sites would twine around, and align them in a noncovalent fashion (Fig.1). The morphologies of the resulting supramolecular assemblies between twimers and conjugated polymers were monitored by UV-Vis, fluorescence spectroscopies, CLSM, PM, and HRTEM. Very interestingly, they afforded novel well-regulated structures..
258. Atsushi Ikeda, Sayuri Ito, Jun Ichi Kikuchi, Kenji Kaneko, Munenori Numata, Kazuo Sakurai, Seiji Shinkai, Solubilization of C 60 by using biopolymers, 55th SPSJ Annual Meeting Polymer Preprints, Japan - 55th SPSJ Annual Meeting, 55, 1888, 2006.01, The ready availability of [60]fullerene (C 60) has increasingly invited exploration of their outstanding new physical and chemical properties. Water-solubilization of C 60 holds potential in the application for various medicinal uses. The use of biomolecules as solubilizing agents of C 60 is preferable in order to be applied for medicinal fields because of little or less toxicity. Taking into account these aims, we have now chosen various polysaccharides as solubilizing agents such as amylose and schizophyllan (SPG). We have discovered that amylose and SPG can solved C 60 in water and form the one dimensional ordered C 60 in the hydrophobic cavities..
259. Masayuki Takeuchi, Osamu Hirata, Tomohiro Ikeda, Masayuki Shibata, Kenji Kaneko, Seiji Shinkai, Supramolecular systems utilizing rotational units, 55th Society of Polymer Science Japan Symposium on Macromolecules 55th SPSJ Symposium on Macromolecules, 55, 4747-4748, 2006.01, We designed portphyrin 1 bearing rotational units at meso-position and porphyrin polymer Pn which has double decker Ce(IV) bisporphyrinate as rotational units and Zn(II) porphyrin as recognition sites alternately. We expected that compound 1 could form one-dimensional supramolecular polymer with Pd complexes, whereas polymer Pn would be expected to fold at the vertex double-decker porphyrin complex in the presence of guests..
260. Koji Inoke, Kenji Kaneko, Zenji Horita, Three-dimensional imaging of shear band produced by ECAP process in Al-Ag alloy, 3rd International Conference on Nanomaterials by Severe Plastics Deformation, NanoSPD3 Nanomaterials by Severe Plastic Deformation, NanoSPD3 - Proceedings of the 3rd International Conference on Nanomaterials by Severe Plastics Deformation, 503-504, 603-608, 2006.01, A significant change in microstracture occurs during the application of severe plastic deformation (SPD) such as by equal-channel angular pressing (ECAP). In this study, intense plastic strain was imposed on an Al-10.8wt%Ag alloy by the ECAP process. The amount of strain was controlled by the numbers of passes. After 1 pass of ECAP, shear bands became visible within the matrix. With increasing numbers of ECAP passes, the fraction of shear bands was increased. In this study, the change in microstructures was examined by three-dimensional electron tomography (3D-ET) in transmission electron microscopy (TEM) or scanning transmission electron microscopy (STEM). With this 3D-ET method, it was possible to conduct a precise analysis of the sizes, widths and distributions of the shear bands produced by the ECAP process. It is demonstrated that the 3D-ET method is promising to understand mechanisms of microstractural refinement using the ECAP process..
261. Teruaki Hasegawa, Shuichi Haraguchi, Munenori Numata, Chun Li, Ah Hyun Bae, Tomohisa Fujisawa, Kenji Kaneko, Kazuo Sakurai, Seiji Shinkai, Poly(diacetylene)-nanofibers can be fabricated through photo-irradiation using natural polysaccharide schizophyllan as a one-dimensional mold, Organic and Biomolecular Chemistry, 10.1039/b510646j, 3, 24, 4321-4328, 2005.12, Schizophyllan interacts with various 1,4-diphenylbutadiyne derivatives to induce their chirally-twisted packing. A series of referential experiments using other polysaccharides (amylose, pullulan, dextran, etc.) and a carbohydrate-appended detergent (dodecyl-β-D-glucopyranoside) indicates that these 1,4-diphenylbutadiyne derivatives are accommodated within a tubular cavity constructed by a helical superstructure of schizophyllan. In these 1,4-diphenylbutadiyne derivatives, 1,4-bis(p-propionamidophenyl)butadiyne can be easily polymerized through UV-irradiation, in which schizophyllan acts as a one-dimensional mold to produce the corresponding poly(diacetylene)s with fibrous morphologies. Detailed investigations on this unique approach to prepare the nanofibers revealed that it includes two individual processes, that is, 1) UV-mediated polymerization of encapsulated 1,4-bis(p-propionamidophenyl) butadiyne to produce immature nanofibers and 2) their reorganization through hydrophobic interfiber interactions into ordered nanofibers. The other 1,4-diphenylbutadiyne derivatives could not be polymerized through UV-irradiation, indicating that the p-propionamido-functionalities play substantial roles for a suitable packing of the monomer for the polymerization. The other 1,4-diphenylbutadiyne derivatives, however, can be also polymerized through γ-ray irradiation in the presence of schizophyllan to give the corresponding poly(diacetylene)-nanofibers, emphasizing the wide applicability of the schizophyllan-based strategy for polymerization of various 1,4-diphenylbutadiyne derivatives..
262. Ryouji Karinaga, Yeonhwan Jeong, Seiji Shinkai, Kenji Kaneko, Kazuo Sakurai, Inclusion of DNA into organic gelator fibers made of amphipathic molecules and its controlled release, Langmuir, 10.1021/la0515524, 21, 21, 9398-9401, 2005.10, When methyl 4,6-O-(p-nitrobenzylidene)-α-D-glucopyranoside (p-NO 2Glu) was dissolved in water, p-NO2Glu molecules self-assembled to form a fiber (elemental fiber), and as a result, the solution became a partially transparent gel. When an equal (or more) amount of DNA was added to the gel, a white and crystalline gel was obtained. Energy-dispersive X-ray spectroscopy coupled with TEM and confocal microscopy suggested that DNA was included in the gel fibers made of p-NO2Glu molecules. The results imply that p-NO2Glu molecules are self-assembled to form an elemental fiber and these elemental fibers and DNA are twisted together to form higher hierarchic fibers. When the complexed gel made of plasmid DNA (pDNA) and p-NO2Glu was added to E. coli T7 S30 extract solution, the pDNA had less expression ability compared with naked one. When we added methyl-β-cyclodextrin (MβCyD), the expression rate was recovered with increasing added amount of MβCyD. The present paper shows inclusion and controlled release of DNA from a novel supporting material of DNA and that technology could play an important role in the development of localized approaches to gene therapy..
263. Munenori Numata, Chun Li, Ah Hyun Bae, Kenji Kaneko, Kazuo Sakurai, Seiji Shinkai, β-1,3-glucan polysaccharide can act as a one-dimensional host to create novel silica nanofiber structures, Chemical Communications, 10.1039/b509285j, 37, 4655-4657, 2005.10, We have demonstrated that the creation of novel silica nanofibers with a uniform diameter is possible by utilizing β-1,3-glucan polysaccharide as a one-dimensional host for monoalkoxysilane; the finding establishes that β1,3-glucan can act not only as a novel one-dimensional host for metal alkoxide polycondensation but also as an interface between inorganic nanofibers and functional organic molecules..
264. R. Karinaga, Y. Jeong, S. Shinkai, K. Kaneko and K. Sakurai, Inclusion of DNA into Organic Gelator Fibers Made of Amphipathic Molecules and Its Controlled Release, Langmuir, 10.1021/;a0515524, 21, 21, 9398-9401, Vol.21 No.21 (2005) pp.9398-9401, 2005.09, [URL].
265. Michihiro Shirakawa, Norifumi Fujita, Takahiro Tani, Kenji Kaneko, Seiji Shinkai, Organogel of an 8-quinolinol platinum(II) chelate derivative and its efficient phosphorescence emission effected by inhibition of dioxygen quenching, Chemical Communications, 10.1039/b506148b, 33, 4149-4151, 2005.09, A newly synthesized 8-quinolinol platinum(II) chelate derivative gelates various organic solvents, and the gel formed shows unique thermo- and solvatochromism of visible and phosphorescent colour in response to a sol-gel phase transition and possesses an attractive ability to inhibit dioxygen quenching of excited triplet states..
266. Kazuo Sakurai, Kazuya Uezu, Munenori Numata, Teruaki Hasegawa, Chun Li, Kenji Kaneko, Seiji Shinkai, β-1,3-glucan polysaccharides as novel one-dimensional hosts for DNA/RNA, conjugated polymers and nanoparticles, Chemical Communications, 10.1039/b506673p, 35, 4383-4398, 2005.09, β-1,3-Glucan polysaccharides have triple-stranded helical structures whose sense and pitch are comparable to those of polynucleotides. We recently revealed that the β-1,3-glucans could interact with certain polynucleotides to form triple-stranded and helical macromolecular complexes consisting of two polysaccharide-strands and one polynucleotide-strand. This unique property of the β-1,3-glucans has made it possible to utilize these polysaccharides as potential carriers for various functional polynucleotides. In paticular, cell-uptake efficiency of the resultant polysaccharide/polynucleotide complexes was remarkably enhanced when functional groups recognized in a biological system were introduced as pendent groups. The β-1,3-glucans can also interact with various one-dimensional architectures, such as single-walled carbon nanotubes, to produce unique nanocomposites, in which the single-walled carbon nanotubes are entrapped within the helical superstructure of β-1,3-glucans. Various conductive polymers and gold nanoparticles are also entrapped within the helical superstructure in a similar manner. In addition, diacetylene monomers entrapped within the helical superstructure can be photopolymerized to afford the corresponding poly(diacetylene)-nanofibers with a uniform diameter. These findings indicate that the β-1,3-glucans are very attractive and useful materials not only in biotechnology but also in nanotechnology. These unique properties of the β-1,3-glucans undoubtedly originate from their inherent, very strong helix-forming character which has never been observed for other polysaccharides..
267. Kenji Kaneko, Won Jin Moon, Koji Inoke, Zenji Horita, Satoshi Ohara, Tadafumi Adschiri, Hiroya Abe, Makio Naito, Characterization of TiO2-Ag nanocomposite particles prepared by spray pyrolysis process using transmission electron microscopy and three-dimensional electron tomography, Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing, 10.1016/j.msea.2005.05.056, 403, 1-2, 32-36, 2005.08, TiO2-Ag nanocomposite particles were prepared by spray pyrolysis of TiO2 (7 nm) dispersed AgNO3 solution. The structures and morphologies of powders were carefully characterized by combination of transmission electron microscopy (TEM) and three-dimensional electron tomography (3D-ET). It was clearly demonstrated by 3D-ET that the TiO2-Ag nanocomposite particle was consisted of well-dispersed Ag nanoparticles within TiO2 matrix. Furthermore, it was shown by high-resolution TEM that the spray pyrolysis was capable of fabricating Ag particles with a few nm in size..
268. Syo Matsumura, T. Horiuchi, Kazuhiro Yasuda, Kenji Kaneko, M. Watanabe, T. Masumoto, Morphological change in FePt nanogranular films induced by irradiation with 100 keV He ions, Scripta Materialia, 10.1016/j.scriptamat.2005.04.044, 53, 4, 441-445, 2005.08, We have investigated the effects of He-ion irradiation on structures of FePt nanoparticles dispersed in thin films with amorphous Al2O 3 matrix. The coarsening of FePt nanoparticles is suppressed under irradiation with 100 keV He+ ions at an elevated temperature, such as 923 K. The delay of particle growth is also recognized in the post-irradiation annealing. On the other hand, He-irradiation is of little assistance in promoting L10 ordering in the nanogranular films at a temperature as low as 573 K..
269. Z. Horita, K. Ohashi, T. Fujita, K. Kaneko, T. G. Langdon, Achieving High Strength and High Ductility in Precipitation-Hardened Alloys, Advanced Materials, 10.1002/adma.200500069, 17, 13, 1599-+, Vol.17 No.13 (2005) pp.1599-1602, 2005.07, [URL].
270. L. Miao, S. Tanemura, Y. Hayashi, M. Tanemura, R.-P. Wang, S. Toh, K. Kaneko, Structural and optical characterization of ZnO single crystalline nanobamboos, International Journal of Modern Physics B, 10.1142/S0217979205031730, 19, 15-17, 2804-2810, Vol.19 No.15-17 (2005) pp.2804-2810, 2005.07, [URL].
271. S. Tanemura, K. Kajino, L. Miao, S. Koide, M. Tanemura, S. Toh, K. Kaneko, M. Mori, Fabrication and structural characterization of TiO nanoparticle soft-landed on substrate by the magnetron sputtering-gas aggregation method, European Physical Journal D, 10.1140/epjd/e2005-00123-8, 34, 1-3, 79-82, Vol.34 No.1-3 (2005) pp.79-82, 2005.07, [URL].
272. Zenji Horita, Kunihiro Ohashi, Takeshi Fujita, Kenji Kaneko, Terence G. Langdon, Achieving high strength and high ductility in precipitation-hardened alloys, Advanced Materials, 10.1002/adma.200500069, 17, 13, 1599-1602, 2005.07, A technique for producing high strength and high ductility in precipitation-hardened alloys at ambient temperatures, based on introduction of intermediate metastable phases into ultrafine-grained microstructures was investigated. The investigation was conducted using an aluminum-silver alloy containing 10.8 wt.% Ag. The precipitation of stable γ-phase particles onto the grain boundaries after aging for 10 h, was observed, with the particles having an average size range of ∼100-200 nm. The results show that sampler processed and aged with this technique, exhibits a stress-strain curve having a region of strain hardening, an extensive uniform strain, and high tensile ductility..
273. S. Tanemura, K. Kajino, L. Miao, S. Koide, M. Tanemura, S. Toh, Kenji Kaneko, M. Mori, Fabrication and structural characterization of TiO nanoparticle soft-landed on substrate by the magnetron sputtering-gas aggregation method, European Physical Journal D, 10.1140/epjd/e2005-00123-8, 34, 1-3, 79-82, 2005.07, We have succeeded to fabricate the thin film mainly or entirely consisting of nano-crystallites TiO on a substrate at room temperature by using the magnetron sputtering combined with the gas aggregation method which has the capability to deposit grown small particles and/or clusters of the desired compound material on the substrate in soft-landed mode. The important experimental parameters to control the growth of TiO particles are identified as partial pressure of additional oxygen gas, growth-reaction distance L td, and LN2 cooling of growth chamber. The smallest averaged diameter of TiO nano-particles is 5.62 nm and size distribution being from 2 to 8 nm under 50 mm of Ltd. The compositional uniformity is confirmed by EDS and EELS. The chemical state of the film observed by Ti 2P XPS peak confirms the primarily growth of TiO and indicates the formation of minor content of amorphous Ti1-xOx and/or Ti1-xC x particularly at the surface of the film..
274. S. Tanaka, M. Shirakawa, K. Kaneko, M. Takeuchi and S. Shinkai, Porphyrin-based Organogels: Control of the Aggregation Mode by a Pyridine-Carboxylic Acid Interaction, Langmuir, 10.1021/la047070u, 21, 6, 2163-2172, Vol.21 No.6 (2005) pp.2163-2172, 2005.06, [URL].
275. K. Kaneko, W.-J. Moon, K. Inoke, Z. Horita, S. Ohara, T. Adschiri, H. Abe and M. Naito, Characterization of TiO2-Ag nanocomposite powders prepared by spray pyrolysis method using three-dimensional electron tomography, Material Science and Engineering A, 10.1016/j.msea.2005.05.056, 403, 1-2, 32-36, Vol.403 No.1-2 (2005) pp.30-36, 2005.06, [URL].
276. K. Kaneko, R. Nagayama, K. Inoke, W.-J. Moon, Z. Horita, Y. Hayashi, T. Tokunaga, Formation of wedge-shaped carbon film by chemical vapor deposition method and observation using transmission electron microscopy, Scripta Materialia, 10.1016/j.scriptamat.2005.03.007, 52, 12, 1205-1209, Vol.52 No.12 (2005) pp.1205-1209, 2005.06, [URL].
277. Y. Ohta M. Kitayama K. Kaneko S. Toh F. Shimizu K. Morinaga, In Situ Measurement of Capacitance: A Method for Fabricating Nanoglass, Journal of the American Ceramics Society, 10.1111/j.1551-2916.2005.00257.x, 88, 6, 1634-1636, Vol.88 No.6 (2005) pp.1634-1636, 2005.06, [URL].
278. Kenji Kaneko, R. Nagayama, K. Inoke, W. J. Moon, Zenji Horita, Y. Hayashi, T. Tokunaga, Formation of wedge-shaped carbon film by chemical vapor deposition method and observation using transmission electron microscopy, Scripta Materialia, 10.1016/j.scriptamat.2005.03.007, 52, 12, 1205-1209, 2005.06, Unusual morphologies of carbon nanofibers (CNFs) fabricated by the microwave plasma-enhanced chemical vapor deposition method were confirmed by transmission electron microscopy. In particular, the presence and distribution of wedge-shaped carbon films, consisting of amorphous carbon and CNFs, were observed by three-dimensional electron tomography (3D-ET), and their growth mechanisms were modeled. High-resolution transmission electron microscopy (HRTEM) revealed the presence of amorphous carbon on carbon nanofibers. Wedge-shaped carbon films are most likely caused by the bridging of individual CNFs by amorphous carbon from plasmarized carbon. The combination of 3D-ET and HRTEM clearly provides a successful strategy for determining 3D morphologies with characteristic sizes on the nanometer scale..
279. Y. Ohta, M. Kitayama, Kenji Kaneko, S. Toh, F. Shimizu, K. Morinaga, In situ measurement of capacitance
A method for fabricating nanoglass, Journal of the American Ceramic Society, 10.1111/j.1551-2916.2005.00257.x, 88, 6, 1634-1636, 2005.06, The capacitance of the Na 2O-SiO 2 glass was measured in situ during heat treatment at various frequencies, 20, 100, 1, 3, 10, and 30 kHz. It was found that the capacitance of the glass abruptly decreases after a certain duration. The glass was quenched at this stage. It was confirmed by the X-ray diffraction and transmission electron microscopy that this decrease of capacitance was associated with the formation of crystallites in the glass matrix. The size of crystallites was observed to be in the range of about 10 nm..
280. L. Miao, S. Tanemura, H. Watanabe, S. Toh and K. Kaneko, Structural and compositional characterization of N2-H2 plasma surface-treated TiO2 thin films, Applied Surface Science, 10.1016/j.apsusc.2004.10.098, 244, 1-4, 412-417, Vol.244 No.1-4 (2005) pp.412-417, 2005.05, [URL].
281. L. Miao, S. Tanemura, H. Watanabe, S. Toh, Kenji Kaneko, Structural and compositional characterization of N2-H 2 plasma surface-treated TiO2 thin films, Applied Surface Science, 10.1016/j.apsusc.2004.10.098, 244, 1-4, 412-417, 2005.05, The structural and compositional properties of three samples such as as-deposited single-phase anatase-TiO2 polycrystalline thin films on slide glass substrates (No. 1), the sample surface-treated by N 2-H2 mixed-gases plasma (No. 2), and the sample being additionally anneal-treated in N2 gases (No. 3), are characterized by transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDS). The primitive lattice cells of three thin films are verified as distorted in comparison with that of bulk from the TEM results. This distortion of primitive lattice cell causes the increase of optical band gap for the films when we compared it with that of bulk, while the decrease of optical band gap should be attributed to the substitution of N into TiO2. Higher concentration of nitrogen in sample No. 3 is confirmed by line-EDS profiles under scanning TEM (STEM) when compared with sample No. 2 and this confirms that plasma surface treatment is an effective way for N-doping in TiO2..
282. S. Matsumura, T. Horiuchi, K. Yasuda, K. Kaneko, M. Watanabe and T. Masumoto, Morphological change in FePt nanogranular films induced by irradiation with 100 keV He ions, Scripta Materialia, 10.1016/j.scriptamat.2005.04.044, 53, 4, 441-445, Vol.53 No.4 (2005) pp.441-445, 2005.04, [URL].
283. Y. Hayashi, T. Kamio, T. Soga, K. Kaneko and T. Jimbo, Efficient nitrogen incorporation into amorphous carbon films by double beam method, Diamond and Related Materials, 10.1016/j.diamond.2005.01.003, 14, 3-7, 970-974, Vol.14 No.3-7 (2005) pp.970-974, 2005.04, [URL].
284. M. Numata, M. Asai, K. Kaneko, T. Hasegawa, K. Sakurai and S. Shinkai, Inclusion of Cut and As-grown Single-walled Carbon Nanotubes in the Helical Superstructure of Schizophyllan and Curdlan (beta-1 3-Glucans), Journal of American Chemical Society, 10.1021/ja044168m, 127, 16, 5875-5884, Vol.127 No.16 (2005) pp.5875-5884, 2005.04, [URL].
285. Munenori Numata, Masayoshi Asai, Kenji Kaneko, Ah Hyun Bae, Teruaki Hasegawa, Kazuo Sakurai, Seiji Shinkai, Inclusion of cut and as-grown single-walled carbon nanotubes in the helical superstructure of schizophyllan and curdlan (β-1,3-glucans), Journal of the American Chemical Society, 10.1021/ja044168m, 127, 16, 5875-5884, 2005.04, We have found that single-chain schizophyllan and curdlan (s-SPG and s-curdlan, respectively) can dissolve as-grown and cut single-walled carbon nanotubes (ag-SWNTs and c-SWNTs, respectively) in aqueous solution. The vis-NIR spectra of the composites suggest that c-SWNTs are dissolved as a bundle, whereas ag-SWNTs exist as one or only a few pieces in the tubular hollow constructed by the helical structure inherent to these β-1,3-glucans. EDX and CLSM measurements and TEM observation established that the distribution map of these polysaccharides overlaps well with the image of SWNTs, indicating that these two components form a composite. Very interestingly, when c-SWNTs were dissolved with the aid of s-SPG or s-curdlan in water, a clear periodical structure with inclined stripes, as detected by AFM, appeared on the fibrous composite surface. Because this periodical structure has never been recognized for the composites with other water-soluble polymers, one can regard that s-SPG or s-curdlan wraps c-SWNTs constructing a helically twined structure. High-resolution TEM observation of an ag-SWNTs/ s-SPG composite gave a clearer image in that two s-SPG chains twine one ag-SWNT and the helical motif is right-handed. When this sample was subjected to the AFM measurement, the composite showed the 2-3 nm height. This height implies that one piece of ag-SWNT is included in the s-SPGs helical structure. As a summary, it has been established that β-1,3-glucans such as s-SPG and s-curdlan not only dissolve SWNTs but also create a novel superstructure on the surface..
286. T. Hasegawa, S. Haraguchi, M. Numata, T. Fujisawa, C. Li, K. Kaneko, K. Sakurai, S. Shinkai, Schizophyllan Can Act as a One-dimensional Host to Construct Poly(diacetylene) Nanofibers, Chemistry Letters, 10.1246/cl.2005.40, 34, 1, 40-41, Vol.34 No.1 (2005) pp.40-41, 2005.03, [URL].
287. Ah Hyun Bae, Munenori Numata, Teruaki Hasegawa, Chun Li, Kenji Kaneko, Kazuo Sakurai, Seiji Shinkai, 1D arrangement of Au nanoparticles by the helical structure of schizophyllan
A unique encounter of a natural product with inorganic compounds, Angewandte Chemie - International Edition, 10.1002/anie.200462810, 44, 13, 2030-2033, 2005.03, (Figure Presented) Forming an orderly line: Au nanoparticles can be aligned in one dimension by their incorporation into the helical structure of a natural polysaccharide, schizophyllan (s-SPG, see picture). The hydrophobic inner cavity of the helix hosts the hydrophobic nanoparticles and aligns the guests along its length (≈ 200 nm)..
288. Yasuhiko Hayashi, T. Kamio, T. Soga, Kenji Kaneko, T. Jimbo, Efficient nitrogen incorporation into amorphous carbon films by double beam method, Diamond and Related Materials, 10.1016/j.diamond.2005.01.003, 14, 3-7, 970-974, 2005.03, Conductivity of amorphous carbon (a-C) was successfully controlled by incorporation of nitrogen atoms using a double beam method (DBM), where both rf nitrogen radical and rf methane plasma sources were controlled separately to optimize the nitrogen incorporation. The as-grown a-C is p-type with a conductivity of 10-11 Ωcm and activation energy (Ea) of 333 meV. The addition of nitrogen atoms under varying nitrogen flow rate from 0 to 2.0 sccm caused the conductivity to reach 10-4 Ωcm as maximum and Ea of 41 meV at 1.5 sccm. The optical band gap is shown to vary only marginally from standard of the as-grown of a-C film (1.39 eV) to 1.45 eV by nitrogen incorporation. The depth profile of a secondary ion mass spectroscopy (SIMS) shows that the uniform concentration of C and N in the films and the sharp interface between nitrogen doped and undoped regions from the doped/undoped sandwich-like a-C structure. Furthermore, the changes in the chemical structure and relative bond fractions as a function of nitrogen flow rate are reported based on the results of an X-ray photoelectron spectroscopy and a Raman spectroscopy..
289. Satoshi Tanaka, Michihiro Shirakawa, Kenji Kaneko, Masayuki Takeuchi, Seiji Shinkai, Porphyrin-based organogels
Control of the aggregation mode by a pyridine-carboxylic acid interaction, Langmuir, 10.1021/la047070u, 21, 6, 2163-2172, 2005.03, To find a new strategy for designing porphyrin-based organogelators, hydrogen-bond-donating (carboxylic acid)/accepting (pyridine) substituants or electron-donating (dialkylamino)/withdrawing (pyridine) substituents were introduced into peripheral positions of a porphyrin (1cp or 1ep, respectively), and the gelation properties were compared with those of symmetrical reference compounds bearing two pyridyl substituents or two ester groups (1pp or 1ee, respectively). It was found that the symmetrical molecules show a solubility that is quite inferior to that of 1cp and 1ep having a dipole moment and precipitate from most organic solvents. 1cp, 1ep, and 1ee formed gels with cyclohexane, methylcyclohexane, and several alcoholic solvents, but scanning electron microscopy (SEM) and transmission electron microscopy (TEM) observations revealed that their superstructures constructed in the organogels are very different. In cyclohexane, 1cp resulted in a sheetlike structure, whereas 1ep and 1ee resulted in a fiberlike structure. The difference is attributed to the two-dimensional interactive forces in 1cp consisting of the porphyrin-porphyrin π-π stacking and the carboxylic acid-pyridine hydrogen bonding. In fact, when the hydrogen-bonding interaction was weakened by alcoholic solvents or by adding pyridine or N,N-(dimethylamino)-pyridine, the sheetlike structure was transfigured to the fiberlike structure. Further detailed analyses of their aggregation modes were conducted by spectroscopic methods such as ultraviolet-visible (UV-vis) absorption, Fourier transform infrared (FT-IR), and X-ray diffraction (XRD). On the basis of these findings, the influence of these peripheral substituents on the gel formation and the aggregation mode was discussed..
290. Y. Hayashi, T. Tokunaga, S. Toh, W. J. Moon, Kenji Kaneko, Synthesis and characterization of metal-filled carbon nanotubes by microwave plasma chemical vapor deposition, Diamond and Related Materials, 10.1016/j.diamond.2004.12.008, 14, 3-7, 790-793, 2005.03, A new type of palladium-based metal-filled carbon nanotubes (MF-CNTs) was fabricated and their characteristics were investigated. The MF-CNTs were grown on Pd/SiO2/Si substrates and Pd/Mo mesh by a microwave plasma-enhanced chemical vapor deposition method using CH4 and H 2 gasses with the technique of bias-enhanced growth method. The structure and composition of Pd-based MF-CNTs were thoroughly investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), and Raman spectroscopy. TEM and EDS analyses showed that MF-CNTs were composed of thick cylindrical graphite walls, and filled with Pd metal inside their roots. Based on TEM characterizations, we proposed a fruitful description for the encapsulating mechanisms..
291. T. Nishi L. Miao S. Tanemura M. Tanemura S. Toh K. Kaneko K. Tajiri, Fabrication and structural characterization of TiO2 aerogel and Au embedded anatase TiO2 xerogel, Transaction of Material Research Society of Japan, Vol.30 No.2 (2005) pp.553-556, 2005.01.
292. K. Shin Y. Yoo S. Lee K. Kaneko and Y. Tomokiyo, Microstructural and Mechanical Properties of TiC TiB2 and VC with Low Carbon Steel Surface Alloy Fabricated by High Energy Electron Beam Irradiation, Material Science Forum, 475-479, 3927-3930, Vol.475-479 No.1-5 (2005) pp.3927-3930, 2005.01.
293. K. Fujita T. Fujita K. Oh-ishi K. Kaneko Z. Horita and T. G. Langdon, Microstructure after Processing by Aging and ECAP for Al-Mg2Si Alloys Containing Excess Si or Mg, Material Science Forum, 475-479, 4047-4050, Vol.475-479 No.1-5 (2005) pp.4047-4050, 2005.01.
294. R. Wakabayashi Y. Kubo M. Takeuchi S. Shinkai K. Kaneko, Alignment of conjugated polymers by supramolecular porphyrin oligomer (2), Polymer Preprints Japan, Vol.54 No.2 (2005) pp.4099-4100, 2005.01.
295. M. Takeuchi S. Tanaka K. Kaneko S. Shinkai, Porphyrin-based supramoleculr assmenbies, Polymer Preprints Japan, Vol.54 No.2 (2005) pp.4281-4282, 2005.01.
296. Y. Kubo, R. Wakabayashi, C. Fujikoshi, K. Kaneko, M. Takeuchi, S. Shinkai, Alignment of conjugated polymers by supramolecular porphyrin oligomer (1), Polymer Preprints Japan, Vol.54 No.2 (2005) pp.4290-4291, 2005.01.
297. C. Fujikoshi Y. Kubo M. Takeuchi S. Shinkai K. Kaneko, Alignment of conjugated polymers by supramolecular porphyrin polymer (3), Polymer Preprints Japan, Vol.54 No.2 (2005) pp.4089-4090, 2005.01.
298. L. Miao S. Tanemura K. Kuno M. Tanemura S. Toh K. Kaneko, A facile sol-gel template approach to synthesis of TiO2 nanotube, Proc. ICCE 12 Nano 13, (2005), 2005.01.
299. S. Tanemura T. Nishi H. Kosaki L. Miao M. Tanemura S. Toh K. Kaneko K. Suzuki, Fabrication and catalysis evaluation of V2O5 aerogel embedded by Pt nano particles, Proc. ICCE 12 Nano 13, (2005), 2005.01.
300. T. Nishi, S. Tanemura, H. Kosaki, L. Miao, M. Tanemura, S. Toh, K. Kaneko, K. Suzuki, Synthesis and catalytic activity of Platinum/Titania aerogel, Proc. ICCE 12 Nano 13, (2005), 2005.01.
301. K. Kaneko, K. Inoke, M. Weyland, P. A. Midgley and Z. Horita, Quantitative Measurement of Local Shear Strain in Nano-scale using 3D-ET, Microscopy and Microanalysis 2005, Vol.11 No.2 (2005) CD-ROM, 2005.01.
302. Y. Hayashi, H. Kanamori, I. Yamada, A. Takasu, S. Takagi and K. Kaneko, Facile fabrication method for p/ n-type and ambipolar transport polyphenylenevinylene-based thin-film field-effect transistors by blending C60 fullerene, Applied Physics Letters, 10.1063/1.1861115, 86, 5, Vol.86 No.5 (2005) pp.052104-1-052104-3, 2005.01, [URL].
303. M. Shirakawa, N. Fujita, T. Tani, K. Kaneko and S. Shinkai, Organogel of an 8-quinolinol platinum(II) chelate derivative and its efficient phosphorescence emission effected by inhibition of dioxygen quenching, Chemical Communications, 10.1039/b506148b, 33, 4149-4151, No.33 (2005) pp.4149-4151, 2005.01, [URL].
304. W-J. Moon, K. Kaneko, S. Toh, M. Saunders, A. Saito, Z. Wang, H. Abe and M. Naito, Structural and analytical characterizations of MgB2 superconducting thin film deposited on differently oriented Al2O3 substrate, Superconducting Science and Technology, 10.1088/0953-2048/18/1/015, 18, 1, 92-100, Vol.18 No.1 (2005) pp.92-100, 2005.01, [URL].
305. S. Tanemura, L. Miao, W. Wunderlich, M. Tanemura, Y. Mori, S. Toh and K. Kaneko, Fabrication and characterization of anatase/rutileTiO2 thin films by magnetron sputtering: a review, Science and Technology of Advanced Materials, 10.1016/j.stam.2004.06.002, 6, 1, 11-17, Vol.6 No.1 (2005) pp.11-17, 2005.01, [URL].
306. Sakae Tanemura, Lei Miao, Wilfried Wunderlich, Masaki Tanemura, Yukimasa Mori, Shoichi Toh, Kenji Kaneko, Fabrication and characterization of anatase/rutile-TiO2 thin films by magnetron sputtering
A review, Science and Technology of Advanced Materials, 10.1016/j.stam.2004.06.002, 6, 1, 11-17, 2005.01, This review article summarizes briefly some important achievements of our recent reserach on anatase and/or rutile TiO2 thin films, fabricated by helicon RF magnetron sputtering, with good crystal quality and high density, and gives the-state-of-the-art of the knowledge on systematic interrelationship for fabrication conditions, crystal structure, composition, optical properties, and bactericidal abilities, and on the effective surface treatment to improve the optical reactivity of the obtained films..
307. Y. Hayashi, H. Kanamori, I. Yamada, A. Takasu, S. Takagi, Kenji Kaneko, Facile fabrication method for pn -type and ambipolar transport polyphenylenevinylene-based thin-film field-effect transistors by blending C60 fullerene, Applied Physics Letters, 10.1063/1.1861115, 86, 5, 1-3, 2005.01, We have demonstrated the solution-processed p - and n -type transports including ambipolar transport organic thin-film transistors (OTFTs), required for complementary thin-film integrated circuit technology, by a facile method of blending the n -type C60 and the p -type [poly(2-methoxy-5-[2'-ethyl-hexyloxy]- 1,4-phenylene vinylene] (MEH-PPV). The carrier transport of PPV-based thin-film field-effect transistors with various C60 compositions are investigated by using the field-effect gated structure. One of the important findings is that tunable electronic properties of OTFTs are achieved by controlling C60 composition using a simple and an inexpensive spin-cast technology. The mobility increases with increase in the C60 composition in both n - and p -type OTFTs. Temperature measurements on n -type OTFTs revealed that transport follows a thermally activated hopping transport model with small activation energy..
308. Teruaki Hasegawa, Shuichi Haraguchi, Munenori Numata, Tomohisa Fujisawa, Chun Li, Kenji Kaneko, Kazuo Sakurai, Seiji Shinkai, Schizophyllan can act as a one-dimensional host to construct poly(diacetylene) nanofibers, Chemistry Letters, 10.1246/cl.2005.40, 34, 1, 40-41, 2005.01, Schizophyllan binds 1,4-bis(p-amidophenyl)butadiyne and acts as a one-dimensional host to produce fibrous polydiacetylene assemblies through UV-irradiation..
309. W. J. Moon, Kenji Kaneko, S. Toh, M. Saunders, A. Saito, Z. Wang, H. Abe, M. Naito, Structural and analytical characterization of as-grown MgB2 film sputtered on differently oriented α-Al2O3 substrate, Superconductor Science and Technology, 10.1088/0953-2048/18/1/015, 18, 1, 92-100, 2005.01, Superconducting MgB2 films were prepared on differently oriented α-Al2O3 substrates, C- and R-planes, which yielded superconducting transition temperatures of about 28 K. The electric resistivity of the MgB2 film deposited on an R-plane substrate is 300 μΩ cm, six times larger than that on a C-plane substrate, 50 μΩ cm. To understand these differences in the electrical properties, various transmission electron microscopes were used to carry out a structural and the compositional analysis. It was shown from selected-area electron diffraction patterns that the microstructure consists of a mixture of columnar MgB2 grains and amorphous phases in the case of the R-plane specimen, while no amorphous phase was present in the case of the C-plane specimen..
310. Chiaki Fujikoshi, Yohei Kubo, Masayuki Takeuchi, Seiji Shinkai, Kenji Kaneko, Alignment of conjugated polymers by supramolecular porphyrin polymer (3), 54th SPSJ Symposium on Macromolecules 54th SPSJ Symposium on Macromolecules - Polymer Preprints, Japan, 54, 4089, 2005.01, Here we report that porphyrin polymer (Twining polymer; Twimer) possessing conjugated polymer binding sites would twine around, and align them in a noncovalent fashion (Fig.1). The morphologies of the resulting supramolecular assemblies between twimers and conjugated polymers were monitored by UV-Visible, fluorescence spectroscopies, CLSM, PM, and HR TEM. Very interestingly, they afforded novel well-regulated network structure..
311. Yohei Kubo, Rie Wakabayashi, Chiaki Fujikoshi, Kenji Kaneko, Masayuki Takeuchi, Seiji Shinkai, Alignment of conjugated polymers by supramolecular porphyrin oligomer (1), 54th SPSJ Symposium on Macromolecules 54th SPSJ Symposium on Macromolecules - Polymer Preprints, Japan, 54, 4290-4291, 2005.01, We here report a preliminary step toward alignment and organization of conjugated polymers by an Aligner molecule with an allosteric function. Aligner molecules 1 and 2, which show positive homotropic allosterism, can bind a guest poly(phenylene-ethynylene) bearing bis(methylaminomethyl)benzene moieties (P1) in their porphinatozinc clefts to organize assemblies of P1. The binding studies were conducted by UV-Vis, fluorescent spectroscopy, AFM and TEM..
312. Rie Wakabayashi, Yohei Kubo, Masayuki Takeuchi, Seiji Shinkai, Kenji Kaneko, Alignment of conjugated polymers by supramolecular porphyrin oligomer (2), 54th SPSJ Symposium on Macromolecules 54th SPSJ Symposium on Macromolecules - Polymer Preprints, Japan, 54, 4099, 2005.01, We proposed a novel approach for aligning and organizing of conjugated polymers by Aligners, which possess several binding sites for conjugated polymers. In this system, however, the supramolecular assemblies between Aligners and polymers are under thermodynamic control and could be destroyed by dilution or other external factors. Aligner 3, which possesses olefins as reaction sites, can bind a guest poly(phenylene-ethynylene) (poly-PPE) and organize assemblies of poly-PPEs. These assemblies were able to be immobilized by metathesis reaction..
313. Keesam Shin, Junghoon Yoo, Sunghak Lee, Kenji Kaneko, Yoshitsugu Tomokiyo, Microstructural and mechanical properties of TiC, TiB2 and VC with low carbon steel surface alloy fabricated by high energy electron beam irradiation, Materials Science Forum, 475-479, V, 3927-3930, 2005.01, Because of its excellent process advantages such as high energy efficiency, short irradiation time and rapid heating, high energy electron beam (HEEB) irradiation is becoming of interest as a future surface modification technology. In this study, surface alloying of TiC, TiB2 and VC ceramic particles with a low carbon steel substrate was carried out using HEEB of 1.4 MeV. Surface alloyed layers of all the specimens were about 2 mm thick and consisted of a melted region, an interface region, a heat affected zone (HAZ) and the matrix. In all the specimens, the hardness at the surface was the highest, and then decreased sharply into the interior reaching the lowest values at the matrix. A remarkable increase in the mechanical properties was observed for the VC surface alloyed specimen. Vanadium carbides of large (∼ 5 μm) and fine sizes (≥ 20 μm) were formed uniformly, which resulted in an increase of hardness to 2-3 times of that of the matrix, and highest wear resistance..
314. Kazuko Fujita, Takeshi Fujita, Keiichiro Oh-ishi, Kenji Kaneko, Zenji Horita, Terence G. Langdon, Microstructures after processing by aging and ECAP for Al-Mg2Si alloys containing excess Si or Mg, Materials Science Forum, 475-479, V, 4047-4050, 2005.01, In this study, severe plastic straining through equal-channel angular pressing (ECAP) is imposed on age-hardenable Al-Mg-Si alloys having two different compositions of excess Si or Mg in the Al-Mg2Si pusedo-binary system. Thereafter, the alloys are subjected to aging and the microstructures are examined using transmission electron microscopy. It is shown that the precipitation behavior is significantly changed through application of ECAP..
315. Masayuki Takeuchi, Satoshi Tanaka, Kenji Kaneko, Seiji Shinkai, Porphyrin-based supramoleculr assmenbies, 54th SPSJ Symposium on Macromolecules 54th SPSJ Symposium on Macromolecules - Polymer Preprints, Japan, 54, 4281-4282, 2005.01, Here we report that the morphology of one-dimensional aggregates composed of porphyrins can be controlled by the peripheral hydrogen-bond donating/accepting groups and van der Waals interactions among alkyl chains introduced in the orthogonal axis toward the porphyrin-porphyrin π π stacking axis. The supramolecular assemblies of porphyrin derivatives were monitored by UV-Visible, XRD, SEM, TEM, and HR-TEM. Very interestingly, they afforded a variety of supramolecular morphologies such as helical ribbon, sphere, doughnut, and cylinder depending on the environmental conditions..
316. H. Abe, T. Kimitani, M. Naito, K. Nogi, T. Fukui, W. J. Moon, Kenji Kaneko, Surface modification of nanoparticles by mechanical milling with glow discharge, Novel Materials Processing by Advanced Electromagnetic Energy Sources, 10.1016/B978-008044504-5/50053-2, 257-260, 2005.01, This chapter discusses the surface modification of nanoparticles by mechanical milling with glow discharge. A new mechanical milling device with glow discharge is developed for aiming of surface modification of nanoparticles without heating. The configuration of this device is based on that of Mechanofusion system, which consists of a rotating chamber and an arm fixed with a certain clearance against the inside wall of the chamber. By applying an electric power into the clearance under controlled ambient and rotating chamber, any particles can be subjected to mechanical forces such as compression and shearing, in glow discharge. Using this device, TiO2 nanoparticle is processed under a gas pressure of 50 Pascals (Pa) of argon (Ar) with 10% ammonia (NH3). TEM-EELS spectrums of the particles indicated that the mechanical milling with glow discharge can promote effective solid-gas reaction without heating. The availability of a novel class of nanoparticles with properties determined by the y high surface/volume ratio offers the possibility of applications ranging from the field of catalysis to the fabrication of photonic materials or devices..
317. K. Nakamura K. Neishi K. Kaneko M. Nakagaki Z. Horita, Development of severe torsion straining process for rapid continuous grain refinement, Materials Transactions, 10.2320/matertrans.45.3338, 45, 12, 3338-3342, Vol.45 No.12 (2004) pp.3338-3342, 2004.12.
318. L. Miao S. Tanemura S. Toh K. Kaneko M. Tanemura, Preparation and characterization of rutile-TiO2 nanorods, Journal of Material Science and Technology, 20, 59-62, Vol.20 (2004) pp.59-62, 2004.12.
319. L. Miao S. Tanemura T. H. Nguyen M. Tanemura S. Toh K. Kaneko M. Kawasaki, An alternative sol-gel method applied to TiO2 coating on Al scale fiber, Journal of Material Science and Technology, 20, 89-92, Vol.20 (2004) pp.89-92, 2004.12.
320. Lei Miao, Sakae Tanemura, Thi Hue Nguyen, Li Luo, Masaki Tanemura, Shoichi Toh, Kenji Kaneko, Masahiro Kawasaki, Alternative sol-gel method applied to TiO2 coating on Al scale fiber, Journal of Materials Science and Technology, 20, SUPPL., 89-92, 2004.12, An alternative sol-gel method has been applied to fabricate anatase and rutile TiO2 coatings uniformly on Al scale fibers with very thin naturally oxidized layer from mixed precursors of Ti tetraisopropoxide, acetyl acetone, deionizer water and ethanol in different molar ratios. The crystal structure of TiO2 coatings on Al scale fiber was confirmed by both XRD and TEM. The surface morphology of the coatings was observed by SEM and the chemical composition of the grown TiO2 was analyzed by EDS in TEM. Anatase coating, having a fine crystalline structure, was grown at 450°C while rutile was being done at 670°C. The TEM results indicated that the fabricated TiO2 coatings consisted of anatase/rutile polycrystalline structures. The optimal fabrication conditions for TiO2 coatings with about 400 nm in thickness on Al scale fibers were established through the characterization results..
321. Y. Yahiro, Kenji Kaneko, T. Fujita, W. J. Moon, Zenji Horita, Crystallographic orientation contrast associated with Ga+ ion channelling for Fe and Cu in focused ion beam method, Microscopy (Oxford, England), 10.1093/jmicro/dfh075, 53, 5, 571-576, 2004.12, In this study, Cu and Fe single crystals are used to examine the change in secondary electron intensity associated with Ga+ ion channelling in a focused ion beam (FIB) system. The single crystals having three different orientations are tilted with respect to the beam incidence and the resulting variation in the secondary electron intensity is measured through the variation in brightness of the crystals. It is shown that intensity minima appear at the beam directions normal to the lower indices of the crystal orientations. The appearance of the intensity minima including the magnitude of the minima is consistent with the prediction based on the event of ion channelling in the crystal and is affected by the crystal structure. The effect of background on the intensity minima is discussed in this study. It is suggested that the presence of the intensity minima may be used to identify a crystal orientation including a crystal structure..
322. Katsuaki Nakamura, Koji Neishi, Kenji Kaneko, Michihiko Nakagaki, Zenji Horita, Development of severe torsion straining process for rapid continuous grain refinement, Materials Transactions, 10.2320/matertrans.45.3338, 45, 12, 3338-3342, 2004.12, This study presents a rapid continuous process for grain refinement in metallic materials through severe plastic deformation (SPD). The principle is described and the process is applied to an Al-5056 alloy and an S45C carbon steel. The new process, designated in this study the severe torsion straining process (STSP), consists of producing a local heated zone in a rod and introducing torsion strain into the zone by rotating one end with the other. The process is continuous because the straining is achieved while the rod is moved so that the heated zone is shifted along the rod. The STSP does not require the use of any die and can be applicable to pipes or wires. Fine-grained structures produced with the STSP are confirmed using optical microscopy and transmission electron microscopy. Tensile properties are measured and compared with the unstrained fully annealed samples. The feasibility of the STSP is discussed with respect to the rotation speed and moving speed..
323. Lei Miao, Sakae Tanemura, Shoichi Toh, Kenji Kaneko, Masaki Tanemura, Preparation and characterization of rutile-TiO2 nanorods, Journal of Materials Science and Technology, 20, SUPPL., 59-62, 2004.12, The controlled growth of densely assembled single-phase rutile-TiO2 nanorods was demonstrated by a heating-sol-gel template process with about -300 nm in diameter and several micrometers in length. Transmission electron microscopic observation reveals these rutile-TiO2 nanorods are the aggregates of many nanocrystallites growing preferentially to the [110] zone axis direction with about 10-30 nm in diameter. The calculation and comparison of d-spacing values with those of bulk values suggest the crystal structure of nanorods close to bulk materials. Selected area electron diffraction and energy dispersive X-ray spectroscopy measurements confirm that the obtained nanorods are rutile-TiO2 nanorods with good compositional uniformity and consist of distinct shape of nanocrystallites with 10-30 nm diameter..
324. L. Miao, S. Tanemura, S. Toh, K. Kaneko, M. Tanemura, Heating-sol-gel template process for the growth of TiO2 nanorods with rutile and anatase structure, Applied Surface Science, 10.1016/j.apsusc.2004.05.201, 238, 1-4, 175-179, Vol.238 No.1-4 (2004) pp.175-179, 2004.11, [URL].
325. L. Miao, S. Tanemura, Y. Kondo, M. Iwata, S. Toh, K. Kaneko, Microstructure and bactericidal ability of photocatalytic TiO2 thin films prepared by rf helicon magnetron sputtering, Applied Surface Science, 10.1016/j.apsusc.2004.05.193, 238, 1-4, 125-131, Vol.238 No.1-4 (2004) pp.125-131, 2004.11, [URL].
326. Lei Miao, Sakae Tanemura, Shoichi Toh, Kenji Kaneko, Masaki Tanemura, Heating-sol-gel template process for the growth of TiO2 nanorods with rutile and anatase structure, Applied Surface Science, 10.1016/j.apsusc.2004.05.201, 238, 1-4 SPEC. ISS., 175-179, 2004.11, Densely assembled nanorods consist of the nanoparticles of rutile and those of anatase have been fabricated successfully by a heating-sol-gel template process, respectively. The size of nanorods varies as a diameter of 100-300nm and a length of several micrometers, which are controllable by the pore size of the template. The similarities and/or differences of the fabricated process and microstructure for rutile and anatase nanorods were discussed. TEM image revealed that anatase nanorods are the aggregates of many indistinct polygonal nanoparticles up to ∼10nm in diameter, while rutile nanorods are the aggregates of irregular octagon and/or hexagon nanoparticles in 10-30nm diameter. XRD, ED and HRTEM lattice image confirmed the nanorods fabricated by the heating-sol-gel process are well assembled by many individual nanoparticles. The nanoparticles in rutile nanorods were larger than those in anatase nanorods possibly due to the different heat-treatment procedure..
327. Lei Miao, Sakae Tanemura, Yoichi Kondo, Misao Iwata, Shoichi Toh, Kenji Kaneko, Microstructure and bactericidal ability of photocatalytic TiO2 thin films prepared by rf helicon magnetron sputtering, Applied Surface Science, 10.1016/j.apsusc.2004.05.193, 238, 1-4 SPEC. ISS., 125-131, 2004.11, The present study investigates the microstructure and bactericidal ability of polycrystalline and epitaxial TiO2 thin films with anatase and rutile structure. Phase formation and the distortion of the lattice of the film compared with bulk are proved by TEM observation. HRTEM images assure the good crystal quality and compact structure of the films prepared by rf helicon magnetron sputtering. This obtained larger band gap due to the lattice deformation could contribute to the better photocatalytic effect of the anatase film. Bactericidal abilities evaluated by the photokilling E. Coli using film stick method under UV irradiation show the following result: Both single and polycrystal anatase films exhibit obvious bactericidal abilities while no distinguishing difference for them. On the other hand, no bactericidal ability is observed for rutile films in this work. The band gap value of rutile film is lower than the energy potential required to O2/O2 - reductions according to the principle proposed by Fujishima et al. This resulted in the observed poor photocatalyst effect of rutile film..
328. T. Hatano, A.-H. Bae, M. Takeuchi, N. Fujita, K. Kaneko, H. Ihara, M. Takafuji, S. Shinkai, Helical structures of conjugate polymers created by oxidative polymerization using synthetic lipid assemblies as templates , Chemistry - A European Journal, 10.1002/chem.200400332, 10, 20, 5067-5075, Vol.10 No.20 (2004) pp.5067-5075, 2004.10, [URL].
329. H. T. Nguyen, L. Miao, S. Tanemura, M. Tanemura, S. Toh, K. Kaneko and M. Kawasaki, Structural and morphological characterization of anatase TiO2 coating on ・Alumina scale fiber fabricated by sol-gel dip-coating method, Journal of Crystal Growth, 10.1016/j.jcrysgro.2004.07.038, 271, 1-2, 245-251, Vol.271 No.1-2 (2004) pp.245-251, 2004.10, [URL].
330. T. Hatano, A.-H. Bae, M. Takeuchi, N. Fujita, K. Kaneko, H. Ihara, M. Takafuji and S. Shinkai, Helical Superstructure of Conductive Polymers as Created by Electrochemical Polymerization Using Synthetic Lipid Assemblies as a Template, Angewandte Chemie International Edition, 10.1002/anie.200351749, 43, 4, 465-469, Vol.43 No.4 (2004) pp.465-469, 2004.10, [URL].
331. L. Miao, S. Tanemura, S. Toh, K. Kaneko, M. Tanemura, Fabrication and photoluminescence of rutile-TiO2 nanorods, Japanese Journal of Applied Physics, 10.1143/JJAP.43.7342, 43, 10, 7342-7345, Vol.43 No.10 (2004) pp.7342-7345, 2004.10, [URL].
332. Lei Miao, Sakae Tanemura, Shoichi Toh, Kenji Kaneko, Masaki Tanemura, Fabrication and photoluminescence of rutile-TiO2 nanorods, Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes, 10.1143/JJAP.43.7342, 43, 10, 7342-7345, 2004.10, Densely assembled single-phase rutile-TiO2 nanorods with diameters of 150-200 nm and lengths of 2-7 μm have been successfully synthesized for the first time by a heating-sol-gel template method. It was found that the heating process of TiO2 sol was beneficial to the single-phase formation of rutile-TiO2 nanorods. Transmission electron microscopic observations reveal that these rutile-TiO2 nanorods are the aggregates of nanocrystallites grown preferentially to the [110] axis with diameters of 10-30 nm. Selected area electron diffraction and energy dispersive X-ray spectroscopy measurements confirm that the obtained nanorods are rutile-TiO2 nanorods with good compositional uniformity and a relatively distinct crystallite shape over the entire length. The photoluminescence result shows a broad band confined in the wavelength range of 400-600 nm. This broad band is thought to originate from bound excitations emission due to the trapping of free excitons by TiO6 octahedra near defects which are possibly oxygen vacancies and/or the color center of Al 3+ impurities..
333. Tsukasa Hatano, Ah Hyun Bae, Masayuki Takeuchi, Norifumi Fujita, Kenji Kaneko, Hirotaka Ihara, Makoto Takafuji, Seiji Shinkai, Helical structures of conjugate polymers created by oxidative polymerization using synthetic lipid assemblies as templates, Chemistry - A European Journal, 10.1002/chem.200400332, 10, 20, 5067-5075, 2004.10, The morphology of conjugate polymers (such as poly(ethylenedioxythiophene), poly (pyrrole), and poly(aniline)) can be controlled in their polymerization processes, by applying the concept of the templating method to oxidative polymerization. As oxidative polymerization of these monomers produces cationic intermediates, the anionic assemblies can act as potential templates due to the mutual electrostatic attractive force. Oxidative polymerization of ethylenedioxythiophene (EDOT), pyrrole, and aniline was carried out using helical superstructures of synthetic lipid assemblies as templates. Interestingly, we have found that oxidative polymerization of these monomers results in novel polymeric aggregates, such as a helical-tape structure and an intertwined helical structure, and that both the right-handed and left-handed helical structures can be created by a change in the hydrophilic head groups. This is the first example of helical superstructures composed of conjugate polymers that have been designed utilizing a convenient templating method..
334. Hue Thi Nguyen, Lei Miao, Sakae Tanemura, Masaki Tanemura, Shoichi Toh, Kenji Kaneko, Masahiro Kawasaki, Structural and morphological characterization of anatase TiO2 coating on χ-Alumina scale fiber fabricated by sol-gel dip-coating method, Journal of Crystal Growth, 10.1016/j.jcrysgro.2004.07.038, 271, 1-2, 245-251, 2004.10, Anatase TiO2 coatings 0.4 μm thick have been successfully fabricated by sol-gel dip-coating process on χ-Al2O3 fibers 100 μm by 10 cm long with a surface fish-scale. This was achieved by adjustment of the sol-gel parameters such as molar ratio of the precursors in TiO2-sols, dip-coating time, drying duration in air, heating processes and number of cyclical repetitions of the process. Two samples were prepared using two sols containing different molar ratios of precursors. XRD, TEM, EDS and SEM characterization confirmed: (1) the similarity of the growth of anatase-TiO2 from two sols under the optimal sol-gel parameters, (2) that the coatings are composed of aggregated crystallites of 10-25 nm in diameter, (3) the good compositional uniformity of Ti in the fabricated anatase-TiO2 crystallites, (4) a surface covering ratio of anatase-TiO2 around the fiber of at least 90%, and (5) that there is a good adherence of the fabricated anatase-TiO2 layer on alumina fiber as evidenced by the lack of cracking and peeling off traces around the boundary between the coating and the fiber..
335. A. Saito, H. Shimakage, A. Kawakami, Z. Wang, K. Kuroda, H. Abe, M. Naito, W. J. Moon, Kenji Kaneko, Masashi Mukaida, S. Ohshima, XRD and TEM studies of as-grown MgB2 thin films deposited on r- and c-plane sapphire substrates, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2003.12.100, 412-414, SPEC. ISS., 1366-1370, 2004.10, As-grown MgB2 thin films were deposited on r-plane (112) and c-plane (001) sapphire substrates by using a carrousel-type magnetron sputtering system. Even though the respective critical temperature and residual-resistivity ratio of the MgB2 films deposited on r- and c-plane sapphire substrates were nearly the same in both cases, the resistivity of the films on the c-plane sapphire substrates, ρ(40 K) about 50 μΩcm, were lower than that on the r-plane sapphire substrates, ρ(40 K) about 300 μΩcm. Standard θ/2θ X-ray diffraction measurements showed that the MgB2 thin films deposited on the c-plane sapphire substrates have c-axis orientation. Cross-sectional transmission electron microscope images showed that the MgB2 thin films deposited on both the r- and c-plane sapphire substrates contain columnar structures. According to the results of selected-area electron-diffraction patterns, the films deposited on the c-plane sapphire substrates had c-axis orientation and the films on the r-plane sapphire substrates including the amorphous MgB 2 also had c-axis orientation. These results indicate that selection of the cut-plane of the sapphire substrates is very important to grow the high-quality as-grown MgB2 thin films..
336. H. Abe, M. Naito, W.J. Moon, K. Kaneko, A. Saito, Z. Wang, Interface structures of AlN/MgB2 thin films sputtered on sapphire c- and r- plane, Journal of Applied Physics, 10.1063/1.1769601, 96, 4, 2343-2346, Vol.96 No.4 (2004) pp.2343-2346, 2004.08, [URL].
337. W. Wunderlich L. Miao M. Tanemura S. Tanemura P. Jin K. Kaneko A. Terai N. Nabatova-Gabin R. Belkada, Ab-initio calculations of the optical band gap of TiO2 thin films, International Journal of Nanoscience, Vol.3 No.4-5 (2004) pp.439-445, 2004.08, [URL].
338. Wilfried Wunderlich, Lei Miao, Masaki Tanemura, Sakae Tanemura, Ping Jin, Kenji Kaneko, Asuka Terai, Nataliya Nabatova-Gabin, Rachid Belkada, Ab-initio calculations of the optical band gap of TiO2 thin films, International Journal of Nanoscience, 3, 4-5, 439-445, 2004.08, Titanium dioxide has been extensively studied in recent decades for its important photocatalytic application in environmental purification. The search for a method to narrow the optical band gap of TiO2 plays a key role for enhancing its photocatalytic application. The optical band gap of epitaxial rutile and anatase TiO2 thin films deposited by helicon magnetron sputtering on sapphire and on SrTiO3 substrates was correlated to the lattice constants. The optical band gap of 3.03 eV for bulk-rutile increased for the thin films to 3.37 on sapphire. The band gap of 3.20 eV for bulk-anatase increases to 3.51 on SrTiO3. In order to interpret this expansion, ab-initio calculations were performed using the Vienna ab-initio software. The calculations for rutile as well anatase show an almost linear increase of the band gap width with decreasing volume or increasing lattice constant a. The calculated band gap fits well with the experimental values. The conclusion from these calculations is, in order to achieve a smaller band gap for both, rutile or anatase, the lattice constant c has to be compressed, and a has to be expanded..
339. H. Abe, M. Naito, W. J. Moon, Kenji Kaneko, A. Saito, Z. Wang, Interface structures of AlN/MgB2 thin films sputtered on sapphire c- and r-plane, Journal of Applied Physics, 10.1063/1.1769601, 96, 4, 2343-2346, 2004.08, The influences of the substrates planes on the interface structures between AlN and MgB2 layers were investigated. These layers were deposited on sapphire substrate with different orientations by a conventional method. Selected-area electron diffraction patterns and high-resolution TEM were applied on the cross-sectional thinned specimens..
340. H. Katsuki, A. Shiraishi, S. Komarneni, W. J. Moon, S. Toh and K. Kaneko, Rapid Synthesis of Monodispersed alpha-Fe2O3 Nanoparticles from Fe(NO3)3 Solution by Microwave Radiation, Journal of the Ceramics Society of Japan, 10.2109/jcersj.112.384, 112, 1307, 384-387, Vol.112 No.7 (2004) pp.384-387, 2004.07, [URL].
341. K. Kaneko, S. Matsumura, A. Sadakata, K. Fujita, W. -J. Moon, S. Ozaki, N. Nishimura and Y. Tomokiyo, Characterization of carbides at different boundaries of 9Cr-steel, Material Science and Engineering A, 10.1016/j.msea.2003.12.065, 374, 1-2, 82-89, Vol.374 No.1-2 (2004) pp.82-89, 2004.06, [URL].
342. Kenji Kaneko, Syo Matsumura, A. Sadakata, K. Fujita, W. J. Moon, S. Ozaki, N. Nishimura, Y. Tomokiyo, Characterization of carbides at different boundaries of 9Cr-steel, Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing, 10.1016/j.msea.2003.12.065, 374, 1-2, 82-89, 2004.06, A combination of structural and analytical investigation by transmission electron microscopy was carried out to characterize carbides formed at two types of boundaries in strain-relieved 9Cr-steel, prior-austenite grain boundary (PAGB) and small-angle grain boundary of subgrain boundary (martensite-lath boundary). Structural characterization by selected-area electron diffraction pattern revealed the presence of fine V-rich MC- and coarse Cr-base M23C6-type carbides at prior-austenite grain boundaries, while fine Mo-base M2C- and coarse M23C6-type carbides at small-angle grain boundaries. Analytical investigation, spectral and mapping analysis, by energy dispersive X-ray spectroscopy (EDS) showed the elemental composition and distribution of carbides at both boundaries. The composition of M23C6-type carbides at both boundaries were almost the same. Even though the processes of M23C6-type carbide formation are expected to be different from each other, the origin of similarities in compositions is ascribed to being the stable phase of M23C6-type carbides. The formation mechanisms of these carbides at different boundaries are also proposed..
343. Y. Yahiro, K. Kaneko, T. Fujita, W.-J. Moon, Z. Horita, Crystallographic orientation contrast associated with Ga+ ion channeling for Fe and Cu in focused ion beam method, Journal of Electron Microscopy, 10.1093/jmicro/dfh075, 53, 5, 571-576, Vol.53 No.5 (2004) pp.571-576, 2004.05, [URL].
344. Shoichi Toh, Kenji Kaneko, Yasuhiko Hayashi, Tomoharu Tokunaga, Won Jin Moon, Microstructure of metal-filled carbon nanotubes, Microscopy (Oxford, England), 10.1093/jmicro/53.2.149, 53, 2, 149-155, 2004.05, Catalysts are usually required to produce carbon nanotubes (CNTs) and play important roles during the growth process. Any catalysts that remain after processing are expected to add extra properties and removal of the catalysts is usually required to achieve the original properties of CNTs. Recently, CNTs have been filled incidentally by catalysts, such as Pb, Sn, Ni and Bi. This has led to success in obtaining additional properties and a few models have been proposed to describe the encapsulating mechanisms. In the present study, CNTs were filled with palladium by a microwave plasma-assisted chemical vapor deposition method. Detailed structural and compositional investigations of these metal-filled CNTs were carried out by transmission electron microscopy to elucidate the growth mechanisms..
345. Y. Hayashi, T. Tokunaga, Y. Yogata, S. Toh, K. Kaneko, T. Soga and T. Jimbo, Corn-shape carbon nanofibers with dense graphite synthesized by microwave plasma-enhanced chemical vapor deposition, Applied Physics Letters, 10.1063/1.1666998, 84, 15, 2886-2888, Vol.84 No.15 (2004) pp.2886-2888, 2004.04, [URL].
346. Y. Hayashi, T. Tokunaga, T. Soga, T. Jimbo, Y. Yogata, S. Toh, Kenji Kaneko, Corn-shape carbon nanofibers with dense graphite synthesized by microwave plasma-enhanced chemical vapor deposition, Applied Physics Letters, 10.1063/1.1666998, 84, 15, 2886-2888, 2004.04, The characterization of bias-enhanced microwave plasma enhanced chemical vapor deposition (BE-PECVD) grown corn-shape carbon nanofibers (CCNF) was studied using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and Raman spectroscopy. The system consisted of a 2.45 GHz, 1.5 kW microwave power supply with a rectangular waveguide that was coupled to a stainless cylindrical growth chamber and molybdenum substrate holder with a radio-frequency graphite heater. The growth period was about 10 minutes, and the CCNF lengths ranges from 0.4 to 1.1 μm depending on the substrate temperature. The results indicate that the optimum substrate temperature is above 550°C to grow..
347. Y. Hayashi, T. Tokunaga, Y. Yogata, S. Toh, Kenji Kaneko, T. Soga, T. Jimbo, Synthesis of corn-shape carbon nanofibers on Si and Mo substrates by bias-enhanced microwave plasma chemical vapor deposition, Diamond and Related Materials, 10.1016/j.diamond.2004.01.020, 13, 4-8, 1198-1202, 2004.04, A new type of corn-shape carbon nanofibers (CCNFs) with metal-free tips was fabricated and their characteristics were investigated. The CCNFs were grown on Ni/SiO2/Si and Ni/Mo mesh substrates by a microwave plasma-enhanced chemical-vapor deposition method using CH4 and H2 gases with the technique of bias enhanced growth method. Transmission electron microscopy and selected area electron diffraction show that CCNFs were composed of thick cylindrical pure graphite walls, and had nanometer-sized tips with roots. The tips' apex angles of CCNFs were dependent on the substrate temperature, as the cone angles of 20, 39 and 60°..
348. L. Miao, S. Tanemura, S. Toh, K. Kaneko, M. Tanemura, Fabrication characterization and Raman study of anatase-TiO2 nanorods by heating sol-gel template process, Journal of Crystal Growth, 10.1016/j.jcrysgro.2003.12.027, 264, 1-3, 246-252, Vol.264 No.1-3 (2004) pp.246-252, 2004.03, [URL].
349. Munenori Numata, Masayoshi Asai, Kenji Kaneko, Teruaki Hasegawa, Norifumi Fujita, Yumiko Kitada, Kazuo Sakurai, Seiji Shinkai, Curdlan and schizophyllan (β-1,3-glucans) can entrap single-wall carbon nanotubes in their helical superstructure, Chemistry Letters, 10.1246/cl.2004.232, 33, 3, 232-233, 2004.03, We have found that s-SPG and curdlan are capable of wrapping SWNTs and the "periodical" helical structure is created, reflecting the helical nature of the SPG main-chain, on the SWNTs surface. The novel SWNTs/β-1,3-glucan composites were characterized by TEM and AFM, which consistently support the view that these β-1,3-glucans wrap SWNTs, creating a helical higher-order structure..
350. Lei Miao, Sakae Tanemura, Shoichi Toh, Kenji Kaneko, Masaki Tanemura, Fabrication, characterization and Raman study of anatase-TiO2 nanorods by a heating-sol-gel template process, Journal of Crystal Growth, 10.1016/j.jcrysgro.2003.12.027, 264, 1-3, 246-252, 2004.03, Densely assembled TiO2 nanorods with a diameter of 150-200nm and a length of several micrometers have been synthesized by a heating-sol-gel template process. The obtained nanorods were characterized to be single anatase-phase by X-ray diffraction. Transmission electron microscopy image revealed that the nanorods were the aggregate of many nanocrystallites with ∼10nm in diameter and indistinct polygonal shape. Selected-area electron diffraction and energy dispersive X-ray spectroscopy results confirmed that the obtained nanorods were anatase-phase with good compositional uniformity and fine crystallinity in the entire length. In addition to the fundamental phonon modes, a weak overtone scattering (B1g) at 801cm-1 was found in Raman scattering study which is usually observed in nano-sized materials. A new process named heating-sol-gel template process for fabrication oxide nanorods with large quantity, good compositional uniformity and fine crystallinity based on a template method was proposed and the above characterization results support the new process is a desirable process..
351. S. Toh, K. Kaneko, Y. Hayashi, T. Tokunaga and W.-J. Moon, Microstructure of metal-filled Carbon nanotube, Journal of Electron Microscopy, 10.1093/jmicro/53.2.149, 53, 2, 149-155, Vol.53 No.2 (2004) pp.149-155, 2004.02, [URL].
352. K. Ohshima, K. Kaneko, T. Fujita and Z. Horita, Determination of absolute thickness and mean-free path of thin foil by z-factor method, Journal of Electron Microscopy, 10.1093/jmicro/53.2.137, 53, 2, 137-142, Vol.53 No.2 (2004) pp.137-142, 2004.02, [URL].
353. L. Miao, S. Tanemura, T. H. Nguyen, M. Tanemura, S. Toh, K. Kaneko, M. Kawasaki, Structural and compositional characterization of rutile-TiO2 nanorods, Proc. IFAM, (2004), 2004.01.
354. S. Tanemura, T. Nishi, H. Kosaki, L. Miao, M. Tanemura, S. Toh, K. Kaneko, Fabrication and structural characterization of inorganic nano-fractal materials from wet gel by super critical drying method, Proc. Thin Films Nanotech, (2004), 2004.01.
355. L. Miao, T. Watanabe, S. Tanemura, T. Jiang, M. Tanemura, M. Mori, S. Toh, K. Kaneko, Fabrication and photochromism study of Ag doped TiO2 thin films, Proc. Thin Films Nanotech, (2004), 2004.01.
356. L. Miao, S. Tanemura, S. Toh, K. Kaneko, T. H. Nguyen, M. Tanemura, Preparation of TiO2 Nanorods by Heating Sol-Gel Template Method, Journal of Ceramics Society of Japan, Vol.112 No.1 (2004) pp.S1329-S1331, 2004.01.
357. Tsukasa Hatano, Ah Hyun Bae, Masayuki Takeuchi, Norifumi Fujita, Kenji Kaneko, Hirotaka Ihara, Makoto Takafuji, Seiji Shinkai, Helical Superstructure of Conductive Polymers as Created by Electrochemical Polymerization by Using Synthetic Lipid Assemblies as a Template, Angewandte Chemie - International Edition, 10.1002/anie.200351749, 43, 4, 465-469, 2004.01, A templating method is used to create conductive polymers that have a helical superstructure. The driving force is an electrostatic interaction between the negative charge in a synthetic lipid and the cationic charge generated in the polymers during oxidative electrochemical polymerization of ethylenedioxythiophene (EDOT) and a pyrrole (see picture; CV = cyclic voltammetry)..
358. Hiroaki Katsuki, Atsunori Shiraishi, Sridhar Komarneni, Wan Jin Moon, Shoichi Toh, Kenji Kaneko, Rapid synthesis of monodispersed α-Fe2O3 nanoparticles from Fe(NO3)3 solution by microwave irradiation, Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan, 10.2109/jcersj.112.384, 112, 1307, 384-387, 2004.01, Monodispersed α-Fe2O3 nanoparticles were prepared at 100°, 120°, and 140°C using 0.02, 0.05, and 0.1 M-Fe(NO3)3-9H2O solutions by microwave-hydrothermal (M-H) and conventional-hydrothermal(C-H) reactions. Compared to the formation of monodispersed α-Fe2O3 particles using the C-H reaction, the M-H reaction led to increased rate of formation by 3 times at 120°C and 5 times at 140°C from 0.1 M-Fe(NO 3)3 solutions. α-Fe2O3 nanoparticles of 23-25 nm in diameter were obtained from 0.02 M solution at 100°C after treatment for 4 h by applying microwaves, which led to the formation of smaller sized particles with a narrow particle size distribution. The coagulation of nano-sized single crystals of 5 to 6 nm in diameter was enhanced by increasing the concentration of Fe(NO3)3 solutions..
359. Lei Miao, Sakae Tanemura, Hiroshige Watanabe, Yukimasa Mori, Kenji Kaneko, Shoichi Toh, The improvement of optical reactivity for TiO2 thin films by N2-H2 plasma surface-treatment, Journal of Crystal Growth, 10.1016/j.jcrysgro.2003.08.010, 260, 1-2, 118-124, 2004.01, To improve the optical reactivity of TiO2 thin film in visible-light region, sputter-deposited anatase film on slide glass substrate with 1200Å film thickness was surface-treated by N2-H 2 mixed gases plasma and additionally anneal-treated in N 2 gases at 400°C for 2h. The absorption edges of plasma-treated sample and plasma plus anneal-treated one shifted from 363nm (3.4eV) to 428nm (2.9eV), and 354nm (3.5eV) to 428nm (2.9eV), while the absorptance for the two corresponding samples increased by 16% and 26%, respectively, in comparison with the as-deposited sample. Spectral absorption is well explained by Tauc-plot extrapolated band-gap using extinction coefficient k obtained from spectroscopic ellipsometry for the surface layers of the three samples, even though in the case of plasma plus anneal-treated sample showed only nominal band-gap value (2.65eV) due to the metallic behavior of extinction coefficient k in lower energy range (2.5eV). X-ray photoemission spectroscopy reveals the formation of TiO2-xNx and TiN deep into about 120Å thickness from the film surface for both plasma-treated and plasma plus anneal-treated samples. Secondary ion mass spectrography also detected high concentration of N element at the surface of the two corresponding samples. From the fact of formation of TiN and TiO2-xNx, N-doping in this work was proved as N substituted O in TiO2 lattice. We confirmed this substitutional N-doping causes the narrowing of band-gap that resulted in the observed significant red shift of the absorption edge to the visible-light region..
360. Kenji Kaneko, Application of three-dimensional electron tomography on a TiO2-Ag composite powder, KONA Powder and Particle Journal, 10.14356/kona.2004007, 22, March, 6, 2004.01.
361. Katsunori Ohshima, Kenji Kaneko, Takeshi Fujita, Zenji Horita, Determination of absolute thickness and mean free path of thin foil specimen by ζ-factor method, Microscopy (Oxford, England), 10.1093/jmicro/53.2.137, 53, 2, 137-142, 2004.01, The ζ-factor method is applied to the thickness determination of thin amorphous specimens where the convergent-beam electron diffraction method is not applicable. Characteristic X-ray intensities are first measured using standard specimens in order to determine ζ-factors. These ζ-factors are then used to determine local thicknesses of an amorphous Si and an amorphous Al alloy. Electron energy-loss spectroscopy (EELS) spectra are acquired at the same positions as for the X-ray measurements. Thus, using the thicknesses measured from the ζ-factor method, the electron meanfree path is determined through the EELS log-ratio method. The mean free path is measured as a function of the collection semi-angle, β, and specimen thickness, and it is also compared with theoretical values. Furthermore, the mean free path of amorphous Si is compared with that of the crystalline Si..
362. L. Miao, S. Tanemura, P. Jin, K. Kaneko, A. Terai and N. Nabatova-Gabain, Simultaneous epitaxial growth of anatase and rutile TiO2 thin films by RF helicon magnetron sputtering, Journal of Crystal Growth, 10.1016/S0022-0248(03)01149-7, 1-2, 100-106, Vol.254 No.1-2 (2003) pp.100-106, 2003.06, [URL].
363. T. Fujita, K. Kaneko and Z. Horita, Diffusion analysis for precipitate free zone (PFZ) in Al-3.7mass%Cu using analytical electron microscopy, Material Transactions, Vol.44 No.7 (2003) pp.1336-1342, 2003.06.
364. Lei Miao, Sakae Tanemura, Ping Jin, Kenji Kaneko, Asuka Terai, Nataliya Nabatova-Gabain, Simultaneous epitaxial growth of anatase and rutile TiO2 thin films by RF helicon magnetron sputtering, Journal of Crystal Growth, 10.1016/S0022-0248(03)01149-7, 254, 1-2, 100-106, 2003.06, Epitaxial films of TiO2 with rutile structure on sapphire and anatase structure on SrTiO3 were simultaneously grown by RF helicon magnetron sputtering of a TiO2 target in Ar atmosphere. X-ray diffraction using θ-2θ scan and pole figure plots confirmed the epitaxial relationship, which were rutile (1 0 1)∥sapphire (1 1 0), (0 1 0)f∥(0 0 1)s, and anatase (0 0 1)∥SrTiO3(0 0 1), (1 0 0)f∥(1 0 0)s, where suffix f and s stand for the film and substrate, respectively. Moreover, observation by transmission electron microscopy identified the epitaxial film growth of single crystalline anatase and rutile structure with slight lattice distortion compared with bulk. The lattice constants of a and b, which were calculated from electron diffraction spots and lattice image in TEM of the films were contracted while that of c being expanded. According to the results of spectroscopic ellipsometry, the films show very high refractive indices (n) at the designated wavelength range in comparison with the past reports on TiO2 thin films. Although there are no bulk references in the anatase case, the values n of the rutile film are comparable to the bulk in the data-book. Such high refractive indices of the films indicate the compact texture of the epitaxial films fabricated by helicon sputtering..
365. S. Tanemura, S. Koide, Y. Senzaki, L. Miao, H. Hirai, Y. Mori, P. Jin, K. Kaneko, A. Terai and N. Nabatova-Gabain, Fabrication and characterization of metal and semiconductor SmS thin films by rf/dc dual magnetron sputtering, Applied Surface Science, Vol.212-213 (2003) pp.279-286, 2003.05, [URL].
366. S. Tanemura, L. Miao, P. Jin, K. Kaneko, A. Terai and N. Nabatova-Gabain, Optical properties of polycrystalline and epitaxial anatase and rutile TiO2 thin films by rf magnetron sputtering, Applied Surface Science, 10.1016/S0169-4332(03)00015-1, 654-660, Vol.212-213 (2003) pp.654-660, 2003.05, [URL].
367. L. Miao, P. Jin, K. Kaneko, A. Terai, N. Nabatova-Gabain and S. Tanemura, Preparation and characterization of polycrystalline anatase and rutile TiO2 thin films by rf magnetron sputtering, Applied Surface Science, 10.1016/S0169-4332(03)00106-5, 255-263, Vol.212-213 (2003) pp.255-263, 2003.05, [URL].
368. S. Tanemura, S. Koide, Y. Senzaki, L. Miao, H. Hirai, Y. Mori, P. Jin, Kenji Kaneko, A. Terai, N. Nabatova-Gabain, Fabrication and characterization of metal and semiconductor SmS thin films by rf/dc dual magnetron sputtering, Applied Surface Science, 10.1016/S0169-4332(03)00113-2, 212-213, SPEC., 279-286, 2003.05, SmS thin films have been individually fabricated on either a-SiO/Si or NaCl substrates at a room temperature by dual targets (dc for metal Sm and rf for pressed powdered chalcogenide Sm2S3) magnetron sputtering of concurrent power control. The fabricated films were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and spectroscopic ellipsometry (SE), respectively, to identify phase formation, structure, and optical band gap. The followings are summarized: (1) polycrystalline metal, intermedium, or semiconductor SmS thin films were identified by XRD, TEM and the phase formation was achieved by controlling the ratio of dc to rf power; (2) the obtained lattice constant of intermedium phase was 5.85 Å from electron diffraction (ED) and 5.91 Å from lattice image. The former value is contraction by 2% compared with bulk semiconductor (5.97 Å), while the later one is contraction by 1% compared with semiconducting one, although this being probably semiconductor which is suggested by the dominated Sm2+ valence state in Sm 3d of XPS; (3) XPS depth profile result confirm that metal Sm and samarium oxide exist near the film-substrate boundary in intermedium case, while stoichiometric SmS is dominant at the surface layer; (4) in semiconductor case, optical band gap is 2.67eV obtained by Tauc plot from SE results..
369. S. Tanemura, L. Miao, P. Jin, Kenji Kaneko, A. Terai, N. Nabatova-Gabain, Optical properties of polycrystalline and epitaxial anatase and rutile TiO2 thin films by rf magnetron sputtering, Applied Surface Science, 10.1016/S0169-4332(03)00015-1, 212-213, SPEC., 654-660, 2003.05, We analyzed successfully the refractive index n, extinction coefficient k, and optical band gap Eg of the fabricated polycrystalline and epitaxial TiO2 films of rutile and anatase films by spectroscopic ellipsometry (SE). The provided samples were prepared by rf magnetron sputtering of TiO2 target with Ar gas plasma under a variety of sputtering parameters such as total pressure, Ar gas flow rate, O2 gas flow rate, applied sputtering power, substrate temperature and substrate materials. The covered wavelength for SE was from 0.75 to 5eV (1653-248nm in wavelength). As the conclusion, the films show higher values of refractive indices than the previously reported ones by other authors. Optical band gaps extrapolated by Tauc plot using the obtained extinction coefficient again show higher values than the known bulk data..
370. L. Miao, P. Jin, Kenji Kaneko, A. Terai, N. Nabatova-Gabain, S. Tanemura, Preparation and characterization of polycrystalline anatase and rutile TiO2 thin films by rf magnetron sputtering, Applied Surface Science, 10.1016/S0169-4332(03)00106-5, 212-213, SPEC., 255-263, 2003.05, Titanium dioxide films with the anatase and rutile single phase were formed on Si substrates by rf sputtering through a precise control of critical parameters. The structure of the films was studied by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and the optical properties were evaluated with spectroscopic ellipsometry (SE). Lattice distortion was found in both anatase and rutile films from TEM observation. The obtained refractive indices n exhibit higher values than those reported for thin films due presumably to the density structure of the sputtered films. Optical band gaps were calculated by Tauc plot using the obtained extinction coefficient separately for anatase and rutile, with values larger than those reported for bulk materials. The reasons for the larger band gap might be due to the strain from lattice distortion..
371. Y. Mori, S. Tanemura, S. Koide, Y. Senzaki, P. Jin, Kenji Kaneko, A. Terai, N. Nabotova-Gabin, Thermo-coloration of SmS thin flims by XPS in situ observation, Applied Surface Science, 10.1016/S0169-4332(03)00373-8, 212-213, SPEC., 38-42, 2003.05, We observed new "thermo-coloration" of the surface layer of SmS film in which it turned from blue-black to gold after annealing at 650 °C for 1h in vacuum. X-ray photoelectron spectroscopy (XPS) was applied to investigate the chemical state of SmS. This phenomenon is different from the previously reported works. The contribution of Sm3+ state dramatically increased upon annealing. This implied that SmS film changes from semiconductor phase to the metal one and Sm oxide. Consequently, it is suggested that new thermo-coloration of SmS film is caused by the phase transition from semiconductor to metal under the presence of Sm oxide..
372. K. Kaneko, S. Matsumura, K. Ikematsu, Y. Kato, Y. Tomokiyo, M. Watanabe and T. Masumoto, Quantitative electron microscopy of FePt nano-crystallites in amorphous Al2O3 matrix, Scripta Materialia, 10.1016/S1359-6462(02)00627-9, 48, 7, 915-920, Vol.48 No.7 (2003) pp.915-920, 2003.04, [URL].
373. Kenji Kaneko, Syo Matsumura, K. Ikematsu, Y. Kato, Y. Tomokiyo, M. Watanabe, T. Masumoto, Quantitative electron microscopy of FePt nano-crystallites in amorphous Al2O3 matrix, Scripta Materialia, 10.1016/S1359-6462(02)00627-9, 48, 7, 915-920, 2003.04, Quantitative characterizations of nanostructures in FePt granular thin films were achieved by transmission electron microscopy with various analytical methods. Significant amounts of Fe and Pt atoms are dissolved within the matrix of Al2O3 in the as-deposited states. These solutioned Fe and Pt atoms play important roles of the structural changes during thermal annealing process..
374. K. Kaneko, K. Fujita, A. Sadakata, Y. Tomokiyo and S. Matsumura, Nanostructural and nanoelemental analysis of metastable M3C-type carbides with alloy-rich layer in heat resistant 2Cr-steel, Scripta Materialia, 10.1016/S1359-6462(02)00534-1, 48, 6, 761-765, Vol.48 No.6 (2003) pp.761-765, 2003.03, [URL].
375. Kenji Kaneko, K. Fujita, A. Sadakata, Y. Tomokiyo, Syo Matsumura, Nanostructural and nanoelemental analysis of metastable M3C-type carbides with alloy-rich layer in heat resistant 2Cr-martensitic steel, Scripta Materialia, 10.1016/S1359-6462(02)00534-1, 48, 6, 761-765, 2003.03, A combination of structural analysis and analytical investigation by transmission electron microscopy was employed to investigate precipitated carbides on 2Cr-steel. Spectral and image analysis by energy dispersive X-ray spectroscopy (EDS), and energy-filtered images in a transmission electron microscopy revealed compositions of precipitated carbides from both boundaries. The presence of concentration gradient of alloy elements within the precipitated carbide, were shown by EDS and energy-filtering transmission electron microscopy. The results indicate that the rate-controlling process should be governed by not only the diffusion of depletion layer but also that of alloy elements within the carbides. It is therefore necessary to consider these phenomena to model the rate-controlling process, for further discussion of the growth mechanisms of the carbides in steels..
376. L. Miao S. Toh K. Kaneko M. Tanemura S. Tanemura, Synthesis and structure characterization of TiO2 nanorods, Proceeding of tenth annual international conference on composites/nano Engineering, (2003) pp.479-480, 2003.01.
377. K. Ohashi T. Fujita K. Oh-ishi K. Kaneko Z. Horita and T. Langdon, Microstructural Control of a Precipitate-Hardenable Al-Ag Alloy using Severe Plastic Deformation, Material Science Forum, 426-4, 2637-2642, Vol.426-432 (2003) pp.2637-2642, 2003.01.
378. Y. Mori S.Tanemura S.Koide Y.Senzaki P. Jin K. Kaneko A. Terai, In Situ Observation of Thermo Coloration of SmS Thin Films by XPS, Proc of ICSFS, (2003), 2003.01.
379. K. Kaneko, T. Kato, M. Kitayama and Y. Tomokiyo, Precipitation of MgOnAl2O3 in Mg-doped a-Al2O3 under Electron Irradiation, Journal of the American Ceramic Society, 86, 1, 161-168, Vol.86 No.1 (2003) pp.161-168, 2003.01, [URL].
380. Takeshi Fujita, Kenji Kaneko, Zenji Horita, Diffusion analysis across grain boundary in Al-3.7 mass%Cu alloy using analytical electron microscopy, Materials Transactions, 10.2320/matertrans.44.1336, 44, 7, 1336-1342, 2003.01, An Al-3.7 mass%Cu alloy was subjected to aging treatment at selected temperatures in the range from 453 to 548 K. Diffusion coefficients of Cu in the alloy were then determined from Cu concentration profiles measured across the grain boundary. A high spatial resolution analytical electron microscope (AEM) capable of forming a 1 nm probe was used to measure the concentration profiles. As the aging temperature is lower, the diffusion coefficients tend to deviate from the values extrapolated from the higher annealing temperatures. It is suggested that this deviation is due to the presence of quenched-in excess vacancies. The concentration profiles were also measured for the boundaries having different misorientation angles. It is shown that the concentration profiles are essentially the same regardless of the misorientation angles and of the boundary characters except for the misorientation angles smaller than a few degrees..
381. Kenji Kaneko, Takeharu Kato, Mikio Kitayama, Yoshitsugu Tomokiyo, Precipitation of MgO·nAl2O3 in Mg-doped α-Al2O3 under electron irradiation, Journal of the American Ceramic Society, 86, 1, 161-168, 2003.01, A number of nanoscale precipitates with random orientations were produced by electron irradiation of polycrystalline Mg-doped α-Al2O3. The precipitation behavior and microstructural changes were observed using in situ high-resolution transmission electron microscopy. A ring pattern corresponding to a polycrystalline fee structure was obtained from the region of these precipitates by selected-area diffraction, and they were identified as nonstoichiometric MgO·nAl2O3. It is believed that Al2O3 with MgO(ss) and/or MgO at the grain boundaries is effectively stabilized by the electron irradiation process, forming the fundamental structure of MgO·nAl2O3. The average size of the precipitates is about 10 nm..
382. Kunihiro Ohashi, Takeshi Fujita, Keiichiro Oh-Ishi, Kenji Kaneko, Zenji Horita, Terence G. Langdon, Microstructural control of a precipitate-hardenable Al-Ag alloy using severe plastic deformation, Materials Science Forum, 426-432, 3, 2637-2642, 2003.01, An Al-10.8wt%Ag alloy was subjected to aging treatment followed by Equal-Channel Angular Pressing (ECAP) (designated process AE) or ECAP followed by aging treatment (designated process EA). Hardness measurements were undertaken with respect to the number of ECAP passes for process AE or with respect to aging time for process EA. Microstructures were examined by transmission electron microscopy (TEM) including X-ray mapping. It is shown that age hardening is observed for the ECAP sample due to the precipitation of very fine particles within the small grains..
383. S. Honda, T. Nagano, K. Kaneko, H. Kodama, Compressive deformation behavior of Al-doped b-SiC at elevated temperature, Journal of the European Ceramics Society, Vol.22 No.6 (2002) pp.979-985, 2002.06, [URL].
384. Sawao Honda, Takayuki Nagano, Kenji Kaneko, Hironori Kodama, Compressive deformation behavior of Al-doped β-SiC at elevated temperature, Journal of the European Ceramic Society, 10.1016/S0955-2219(01)00406-X, 22, 6, 979-985, 2002.06, Compression tests were performed on Al-doped β-SiC fabricated by hot-pressing using pyrolyzed polycarbosilane at 2123-2223 K in He. An amorphous phase was clearly seen at the grain boundaries in as-sintered specimens. The stress exponents were from 1.1 to 1.4 in the temperature range 2123-2223 K. Strain hardening was observed under all experimental conditions. The phase transformation from β to α was not observed even after the compression tests. The amorphous phase at grain boundaries was vaporized from specimen surfaces during testing. The deformation behavior was influenced by the dynamic change of grain-boundary structure..
385. Y. Hayashi, M. M. Rahman, K. Kaneko, T. Soga, M. Umeno and T. Jimbo, Deposition of amorphous CNx by d.c. and rf plasma sputtering using a rf radical nitrogen beam source, Diamond and Related Materials, 10.1016/S0925-9635(02)00013-4, 11, 3-6, 1178-1182, Vol.11 No.3-6 (2002) pp.1178-1182, 2002.03, [URL].
386. Y. Hayashi, M. M. Rahman, Kenji Kaneko, T. Soga, M. Umeno, T. Jimbo, Deposition of amorphous CNx by d.c. and rf plasma sputtering using a rf radical nitrogen beam source, Diamond and Related Materials, 10.1016/S0925-9635(02)00013-4, 11, 3-6, 1178-1182, 2002.03, Amorphous CNx thin films were deposited by d.c. and rf Ar plasma sputtering combined with a nitrogen rf radical beam source which supplies active nitrogen species to the growing film surface. The dependence modifications of the optical and the structural properties on nitrogen incorporation were investigated using ultraviolet-visible spectroscopy, X-ray photoelectron spectroscopy, a four-point-probe method and electron energy-loss spectroscopy. For the rf-sputtered films, the optical band gap was found to increase with the increase in the nitrogen content. For the d.c.-sputtered films, the optical gap first decreased to zero at low nitrogen content, and then increased with a further increase in the nitrogen content. C-K energy-loss near-edge structure (ELNES) showed a slight broadening on the lower energy side. The local environment of C and N atoms are almost similar as observed by comparing the C-K and N-K ELNESs..
387. T. Nagano, K. Kaneko, G-D. Zhan, M. Mitomo and Y-W. Kim, Superplastic Behavior of Liquid-Phase Sintered b-SiC with Oxynitride Glasses in an N2 Atmosphere, Journal of the European Ceramics Society, Vol.22 No.2 (2002) pp.263-270, 2002.02, [URL].
388. Takayuki Nagano, Kenji Kaneko, Guo Dong Zhan, Mamoru Mitomo, Young Wook Kim, Superplastic behavior of liquid-phase sintered β-SiC prepared with oxynitride glasses in an N2 atmosphere, Journal of the European Ceramic Society, 10.1016/S0955-2219(01)00258-8, 22, 2, 263-270, 2002.02, The superplastic behavior of liquid-phase sintered β-SiC with oxynitride glasses was compared in compression and tension tests at 1973-2048 K in an N2 atmosphere. Strain hardening was observed under all experimental conditions. Stress exponents in the compression tests of SiC with different additives were about 2 in the temperature ranging from 1973 to 2023 K. Amorphous phases were observed at the grain boundaries and at multi-grain junctions in the as-sintered materials. Superplastic behavior was greatly influenced by grain growth, vaporization of grain-boundary phase and formation of crystalline phase during tensile deformation..
389. Kenji Kaneko, N. Honbe, M. Matsumoto, Y. Yasutomi, T. Saitoh, Y. Takigawa, Triple-layered, thick glassy grain boundaries in porous cordierite ceramics, Acta Materialia, 10.1016/S1359-6454(01)00346-9, 50, 3, 597-604, 2002.02, Mechanical tests and microstructural investigations were performed on porous cordierite ceramics. Four-point bending tests were carried out both in air and in water. It was shown that the mechanical strength was strongly influenced by the experimental conditions. Triple-layered, thick amorphous grain boundaries were observed by high-resolution transmission electron microscopy. The composition of each layer as measured by energy dispersive X-ray spectroscopy was shown to be different. It is concluded that applying an external stress causes water-induced stress corrosion cracking preferentially occurring at the amorphous grain boundaries and at the triple grain junctions. This may have caused the dramatic decrease in the mechanical strength in water compared with that in air..
390. T. Katsuya K. Oomura Y. Tomokiyo K. Kaneko and M. Watanabe, Quantitative Analysis of Images Obtained by EF-TEM Method, Proc. of ICEM 15, (2002) CD-ROM, 2002.01.
391. A. Sadakata K. Kaneko K. Fujita Y. Tomokiyo and S. Matsumura, Characterization of Precipitated Carbides at the boundaries, Proc. of ICEM 15, (2002) CD-ROM, 2002.01.
392. K. Oh-ishi Y. Hashi A. Sadakata K. Kaneko Z. Horita T. G. Langdon, Microstructural control of an Al-Mg-Si alloy using equal-channel angular pressing, Material Science Forum, 396-4, 333-338, Vol.396 No.4 (2002) pp.333-338, 2002.01.
393. M. Matsumoto, K. Kaneko, Y. Yasutomi, S. Ohara, T. Fukui and Y. Ozawa, Synthesis of TiO2-Ag composite powder by spray pyrolysis, Journal of Ceramic Society Japan, Vol.110 No.1 (2002) pp.60-62, 2002.01.
394. Matsumoto Mineaki, Kenji Kaneko, Yasutomi Yoshiyuki, Ohara Satoshi, Fukui Takehisa, Ozawa Yasuo, Synthesis of TiO2-Ag composite powder by spray pyrolysis, Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan, 110, 1277, 60-62, 2002.01, Spray pyrolysis was used to fabricate TiO2-Ag composite powders for application in oxide barrier between filaments of superconducting multifilamentary tapes. The powders were prepared from an aqueous solution of TiO2 sol and AgNO3. SEM and TEM observations revealed that the average size of the synthesized powder was less than 1 μm and consisted of well-dispersed fine primary particles of TiO2 and Ag. It was clearly observed that the microstructure of the particles was altered by conditions of heat treatment..
395. Keiichiro Oh-Ishi, Yukihiro Hashi, Akiko Sadakata, Kenji Kaneko, Zenji Horita, Terence G. Langdon, Microstructural control of an Al-Mg-Si alloy using equal-channel angular pressing, Materials Science Forum, 396-402, 1, 333-338, 2002.01, Severe plastic deformation using the process of equal-channel angular pressing (ECAP) was applied to an age-hardenable Al-Mg-Si alloy containing precipitate particles. Subsequent microstructual changes were examined using conventional transmission electron microscopy and energy-filtered transmission electron microscopy. It is shown that metastable rod-shaped β' particles are fragmented into round-shaped particles by the severe straining and there is a dissolution of the particles with an increase in the imposed strain. Further aging leads to the formation of cube-shaped particles in sample where the dissolution of particles occurs. It is also shown that the aging is significantly accelerated, and Si particles are formed, if it is undertaken using samples subjected to ECAP..
396. D. V. Shtansky, K. Kaneko, A. N. Sheveiko, Y. Ikuhara and E. A. Levashov, Characterization of Nanocrystalline Multiphase Ti-Al-B-N Thin Films with Extremely Small Grain Size, Surface and Coatings Technology, Vol.148 No.2-3 (2001) pp.206-215, 2001.12, [URL].
397. D. V. Shtansky, Kenji Kaneko, Y. Ikuhara, E. A. Levashov, Characterization of nanostructured multiphase Ti-Al-B-N thin films with extremely small grain size, Surface and Coatings Technology, 10.1016/S0257-8972(01)01341-X, 148, 2-3, 206-215, 2001.12, The microstructure and chemical composition of nanostructured multiphase Ti-Al-B-N films deposited by DC magnetron sputtering of a multiphase composite Ti-Al-B-N target (five phases) in a gaseous mixture of argon and nitrogen were studied by means of Auger electron spectroscopy, X-ray diffraction, conventional and high-resolution transmission electron microscopy and electron energy-loss spectroscopy. The (Ti + Al)/B ratio of films deposited at low nitrogen partial pressure replicates that of the target. At higher values of nitrogen partial pressure, the target is preferentially sputtered. The chemical composition of the films is not influenced significantly by either the substrate temperature or the bias voltage, whereas the phase composition is strongly affected by the PVD process parameters. Evidence for the formation of mixtures of nanocrystalline (Ti,Al)N, TiB2 and h-BN phases in an amorphous matrix is presented. Most of the Ti-Al-B-N films show a grain size in the range 0.6-4 nm. The grain size reduces further to 0.3-1 nm with decreasing N content (TiAl0.2B0.7N0.7 film). This is the smallest grain size determined from TEM investigations which has hitherto been observed, being only one three unit cells in dimension. Evidence for the ordered structure of grain boundaries in the nanostructured TiAl0.3B0.5N1.9 film is obtained. The amorphous phase forms as individual grains rather than as a thin, intergranular amorphous layer of uniform thickness, even though only a limited number of grain boundaries were studied in detail. The applicability of the equilibrium phase diagram for the prediction of the phase composition in the Ti-Al-B-N films is also discussed..
398. Y. Tai, M. Watanabe, K. Kaneko, S. Tanemura, T. Miki, J. Murakami and K. Tajiri, Preparation of Gold Cluster/Silica Nanocomposite Aerogel via Spontaneous Wet-Gel Formation, Advanced Materials, Vol.13 No.21 (2001) pp.1611-1614, 2001.11, [URL].
399. Y. Tai, M. Watanabe, Kenji Kaneko, S. Tanemura, T. Miki, J. Murakami, K. Tajiri, Preparation of gold cluster/silica nanocomposite aerogel via spontaneous wet-gel formation, Advanced Materials, 10.1002/1521-4095(200111)13:21<1611::AID-ADMA1611>3.0.CO;2-V, 13, 21, 1611-1614, 2001.11, Preparation of gold cluster/silica nanocomposite aerogel was performed using spontaneous wet-gel formation technique. The gold particles were immobilized on the silica structure to the extent that they were not flushed out upon supercritical CO2 drying. It is found that the gold particles are absorbed in a silica wet gel in toluene or hexane solution resulting in the formation of nanocomposite gel..
400. T. Nagano, H. Gu, K. Kaneko, G-D. Zhan, M. Mitomo and F. Wakai, Effect of Dynamic Microstructural Change on Deformation Behavior in Liquid-Phase-Sintered b-SiC with Al2O3-Y2O3-CaO Additions, Journal of the American Ceramic Society, Vol.84 No.9 (2001) pp.2045-2050, 2001.09, [URL].
401. A. Sadakata K. Kaneko M. Watanabe Y. Tomokiyo, Application of EF-TEM Spectrum-Imaging on grain boundaries of Cr steel, Proc. Int. Sympo. on Advanced Physical Fields, (2001) pp.265-268, 2001.01.
402. Takayuki Nagano, Hui Gu, Kenji Kaneko, Guo Dong Zhan, Mamoru Mitomo, Effect of Dynamic Microstructural Change on Deformation Behavior in Liquid-Phase-Sintered Silicon Carbide with Al2O3-Y2O3-CaO Additions, Journal of the American Ceramic Society, 84, 9, 2045-2050, 2001.09, Nanocrystalline β-SiC with additions of 7 wt% Al2O3, 2 wt% Y2O3, and 1 wt% CaO was subjected to tensile deformation to study its microstructural behavior under the dynamic process. The liquid-phase-sintered body had a relative density of >97% and an average grain size of 170 nm. Tension tests were conducted at initial strain rates ranging from 2 × 10-5 to 5 × 10-4 s-1, in the temperature range 1973-2023 K, in both argon and N2 atmospheres. Although grain-boundary liquids formed by the additions vaporized concurrently with the decomposition of SiC and extensive grain growth, the maximum tensile elongation of 48% was achieved in argon. Annealing experiments under the same conditions revealed that vaporization and grain growth were both dependent on experimental time. Therefore, high strain rates suffered less from the hardening effect when cavitation damage was more severe. Testing in an N2 atmosphere brought about crystallization of the grain-boundary phase and prevented severe vaporization; however, fracture occurred at only 8% elongation. Grain-boundary sliding was still the dominant mechanism for deformation..
403. K. Kaneko and N. Kondo, TEM studies of reaction-bonded Si3N4/SiC composites, Grain Boundary Engineering in Ceramics, Vol.118 (2001) pp.391-397, 2001.01.
404. T. Nagano, K. Kaneko, G-D. Zhan and M. Mitomo, Effect of Atmosphere on Weight Loss in Sintered Silicon Carbide during Heat Treatment, Journal of the American Ceramic Society, Vol.83 No.11 (2000) pp.2781-2787, 2000.11, [URL].
405. Takayuki Nagano, Kenji Kaneko, Guo Dong Zhan, Mamoru Mitomo, Effect of atmosphere on weight loss in sintered silicon carbide during heat treatment, Journal of the American Ceramic Society, 83, 11, 2781-2787, 2000.11, Heat treatment was performed on β-SiC with different sintering additives in the temperature range 1873-2073 K, in both argon and nitrogen-gas atmospheres. In the case of the specimens heat-treated at 2073 K in argon, the weight loss was more than the total weight of the sintering additives, except for B,C-doped β-SiC. On the other hand, weight loss was suppressed by about one-third to one-half in nitrogen gas. Weight loss depended mainly on the reaction at the interface between the SiC grains and the grain-boundary phase..
406. T. Nagano, K. Kaneko, G-D. Zhan and M. Mitomo, Superplasticity of Liquid-Phase Sintered b-SiC with the Addition of Al2O3-Y2O3-AlN, Journal of the American Ceramic Society, Vol.83 No.10 (2000) pp.2497-2502, 2000.10, [URL].
407. Takayuki Nagano, Kenji Kaneko, Guo Dong Zhan, Mamoru Mitomo, Superplasticity of liquid-phase-sintered β-SiC with Al2O3-Y2O3-AlN additions in an N2 atmosphere, Journal of the American Ceramic Society, 83, 10, 2497-2502, 2000.10, Compression and tension tests were performed on liquid-phase-sintered β-SiC fabricated by hot-pressing, using ultrafine powders, at 1973-2048 K in an N2 atmosphere. Amorphous phases were observed at the grain boundaries and at multigrain junctions in the as-sintered material. Strain hardening was observed under all experimental conditions. Stress exponents in the compression test were 1.7-2.1 in the temperature range 1973-2023 K. A maximum tensile elongation of 170% was achieved at the initial strain rate of 2×10-5 s-1 at 2048 K..
408. M. Kusunoki, T. Suzuki, T. Hirayama, K. Kaneko and N. Shibata, A formation mechanism of carbon nanotube films on SiC (0001), Applied Physics Letters, Vol.77 No.4 (2000) pp.531-533, 2000.07, [URL].
409. M. Kusunoki, T. Suzuki, T. Hirayama, N. Shibata, Kenji Kaneko, A formation mechanism of carbon nanotube films on SiC(0001), Applied Physics Letters, 10.1063/1.127034, 77, 4, 531-533, 2000.07, We report a remarkable difference of decomposed structures on the Si(0001) and C(0001̄ faces of a SiC single crystal observed by using a cross-sectional high-resolution electron microscopy. An aligned carbon nanotube (CNT) film was fabricated on the C face perpendicular to the surface after heating at 1700 °C for half an hour in a vacuum. On the contrary, a very thin layer of graphite sheets parallel to the surface was formed on the Si face under the same condition. It is proposed that the growth of CNTs is determined by the generation of nanocaps at the initial stage, by comparing the difference of the decomposition mechanisms on the both faces..
410. K. Kaneko, S. Honda, T. Saitoh, T. Nagano and S. Tsurekawa, Analytical characterization of both pre- and post-deformed Al-doped sintered beta-SiC, Material Science Engineering A, Vol.285 No.1-2 (2000) pp.136-143, 2000.06, [URL].
411. Kenji Kaneko, Sawao Honda, Takayuki Nagano, Tomohiro Saitoh, Analytical investigation of grain boundaries of compressive deformed Al-doped sintered β-SiC, Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing, 285, 1-2, 136-143, 2000.06, Series of analytical investigations were carried out to study the effect of deformation process at grain boundaries of Al-doped β-SiC (β-SiC[Al]). Three specimens, as-sintered, annealed and compressed β-SiC[Al] specimens were provided. Grain boundaries were observed by a high-resolution transmission electron microscope (HRTEM) and analytically investigated by energy dispersive X-ray spectroscopy (EDS) also electron energy loss spectroscopy (EELS) attached on a scanning transmission electron microscope (STEM). Glass phases Al-Si-O were commonly observed from the grain boundaries of the as-sintered specimen. It was also analyzed by EELS measurements that the amorphous phases were occasionally modified to form the fourfold coordinated aluminum-oxide by the compressive deformation. On the other hand, there were little traces of Al and O atoms observed from annealed specimen which suggests the vaporization of amorphous glass phase from the grain boundaries, due to the elevated temperature..
412. T. Kato, K. Nunome, K. Kaneko and H. Saka, Formation of z phase at an interface between an Fe substrate and a molten 0.2 mass % Al-Zn during galvannealing, Acta Materialia, Vol.48 No.9 (2000) pp.2257-2262, 2000.05, [URL].
413. N. Kondo K. Kaneko Y. Suzuki and T. Oji, Middle Stage Heat Treatment for Microstructure Control of Reaction-Bonded Silicon Nitride-Silicon Carbide Composite, Journal of Ceramic Society Japan, Vol.108 No.5 (2000) pp.445-448, 2000.05.
414. K. Kaneko and K. Kakimoto, HRTEM and ELNES Analysis of Polycarbosilane-derived Si-C-O bulk ceramics, Journal of Non-Crystalline Solids, Vol.270 No.1-3 (2000) pp.181-190, 2000.05, [URL].
415. T. Kato, K. Nunome, Kenji Kaneko, H. Saka, Formation of the ζ phase at an interface between an Fe substrate and a molten 0.2 mass% Al-Zn during galvannealing, Acta Materialia, 10.1016/S1359-6454(00)00037-9, 48, 9, 2257-2262, 2000.05, An interstitial free (IF) steel was dipped in a bath of molten Zn containing 0.2 mass% Al. The asdipped (galvanized) steel was then annealed above the melting point of Zn (galvannealed), say at 773 K, for a period ranging from 1 to 30 s. Evolution of the microstructure of the Zn-containing coating was examined by transmission electron microscopy (TEM) and the chemical composition around the Zn(Al)/Fe interface was analyzed by energy dispersion spectroscopy (EDS) in a dedicated scanning transmission electron microscope (STEM). In the as-dipped (galvanized) steel a continuous layer of Fe2Al5 existed at the Zn(Al)/Fe interface, but no Fe-Zn intermetallic compounds were observed. Galvannealing at 773 K for 1 s resulted in the formation of the ζ phase at the Zn(Al)/Fe2Al5 interface, which grew at the expense of the Zn(Al) coating during the subsequent galvannealing. Possible mechanisms of nucleation of Fe-Zn intermetallic compounds are discussed..
416. Kenji Kaneko, Ken Ichi Kakimoto, HRTEM and ELNES analysis of polycarbosilane-derived Si-C-O bulk ceramics, Journal of Non-Crystalline Solids, 270, 1-3, 181-190, 2000.05, A series of analyses by high-resolution transmission electron microscopy (HRTEM) and electron energy-loss spectroscopy (EELS) has been carried out to investigate the nanostructure and the chemical bonding of Si-C-O bulk ceramics prepared by pyrolysis of oxygen-controlled polycarbosilane (PCS). HRTEM revealed that the Si-C-O ceramics with higher oxygen content tended to keep an amorphous microstructure. EELS allowed the examination of energy-loss, near-edge-structures (ELNES) that detected clear transition signals of the chemical bonding around Si atoms from Si-C bonding to Si-O bonding with an increase of oxygen content. The microstructure of the PCS-derived Si-C-O bulk ceramics is characterized as a function of oxygen content..
417. K. Kaneko, M. Kawasaki, T. Nagano, N. Tamari and S. Tsurekawa, Determination of the chemical width of grain boundaries of boron- and carbon-doped hot-pressed beta-SiC by HAADF imaging and ELNES line-profile, Acta Materialia, Vol.48 No.4 (2000) pp.903-910, 2000.02, [URL].
418. Kenji Kaneko, M. Kawasaki, T. Nagano, N. Tamari, S. Tsurekawa, Determination of the chemical width of grain boundaries of boron- and carbon-doped hot-pressed β-SiC by HAADF imaging and ELNES line-profile, Acta Materialia, 10.1016/S1359-6454(99)00393-6, 48, 4, 903-910, 2000.02, A residue of sintering additives is often found at the grain boundaries in sintered ceramics. This can be used to determine the macroscopic properties of the sintered polycrystalline materials. A combination of both high-angle annular dark-field (HAADF) imaging and energy-loss near edge-structure (ELNES) line-profile methods was carried out to measure the chemical width of grain boundaries using the sintering additives. Application of both HRTEM and HAADF imaging methods for boron- and carbon-doped hot-pressed SiC leads to the identification of the structural differences either within the matrix or at the grain boundaries very clearly. Additionally, EELS analysis was also carried out to identify the chemistries and bondings at the grain boundaries. The segregation of both boron and nitrogen is clearly shown, as well as the chemical width measured at the grain boundaries by the ELNES line-profile method. Incorporation of nitrogen within the grain interior was also detected by ELNES analysis..
419. K. Kaneko T. Saitoh and S. Tsurekawa, Determination of grain boundary structure by EELS of Al-doped sintered b-SiC, Material Science Forum, Vol.294 No.2 (2000) pp.269-272, 2000.01.
420. T. Nagano K. Kaneko G-D. Zhan and M. Mitomo, Superplasticity of Liquid-Phase Sintered beta-SiC, Superplasticity-Current Status and Future Potential, Vol.601 (2000) pp.133-138, 2000.01.
421. Naoki Kondo, Kenji Kaneko, Yoshikazu Suzuki, Tatsuki Ohji, Middle stage heat treatment for microstructure control of reaction-bonded silicon nitride-silicon carbide composite, Nippon Seramikkusu Kyokai Gakujutsu Ronbunshi/Journal of the Ceramic Society of Japan, 108, 5, 445-448, 2000.01, A silicon nitride-silicon carbide composite was fabricated from silicon and carbon powders by reaction-bonding and post-hot-pressing procedures. The fabricated specimens had a nanocomposite-like microstructure with β-silicon nitride and β-silicon carbide. For some specimens, middle-stage heat treatment was applied before hot-pressing, which resulted in microstructure formation with large and elongated silicon nitride grains. With this microstructure, the specimens subjected to the middle stage heat treatment exhibited much higher fracture toughness than those not subjected to it..
422. T. Nagano, Kenji Kaneko, G. D. Zhan, M. Mitomo, Superplasticity of liquid-phase sintered β-SiC, Quaternary International, 601, 133-138, 2000.01, The compression and the tension tests of liquid-phase sintered β-SiC fabricated by hot-pressing using ultra fine powders were performed at 1973 K approx. 2048 K in N2 atmosphere. Amorphous phases were observed at the grain boundaries and at multi-grain junctions in the assintered material. Strain hardening was observed under all experimental conditions. Stress exponents in the compression test were from 1.7 to 2.1 in the temperature ranging from 1973 K to 2023 K. A maximum tensile elongation of 170% was achieved at the initial strain rate of 2 X 10-5 s-1 at 2048 K..
423. K. Kaneko J. Yuan M. Yoshiya I. Tanaka, Chemical Bonding of intergranular amorphous layers in high-purity beta-SiC ceramics, Inst. Phys. Conf. Ser. (EMAG 99), Vol.161 (1999) pp.59-62, 1999.12.
424. Kenji Kaneko, T. Saitoh, S. Tsurekawa, Characterization of grain boundaries of Al-doped sintered β-SiC by both HRTEM and STEM, Materials Science Forum, 294-296, 269-272, 1999.12, Both high-resolution transmission electron microscope (HRTEM) and scanning transmission electron microscope (STEM) were carried out to observe the structure and chemistry of grain boundaries of Al-doped sintered β-SiC. Two specimens, an as-sintered and an compressed Al-doped sintered β-SiC specimens, were provided. Although, it was shown by energy dispersive X-ray spectroscopy (EDS) that Al and O segregated at grain boundaries of both specimens, it was discovered by electron energy loss spectroscopy (EELS) that the chemistry of grain boundaries of both specimens were different..
425. M. Yoshiya, I. Tanaka, K. Kaneko and H. Adachi, First Principles Calculations of Chemical Shifts in ELNES/NEXAFS of Titanium Oxides, Journal of Physics: Condensed Matter, Vol.11 No.16 (1999) pp.3217-3228, 1999.04, [URL].
426. M. Kusunoki, T. Suzuki, K. Kaneko and M. Ito, Formation of Self-Aligned Carbon Nanotube Films by Surface Decomposition of Silicon Carbide, Philosophical Magazine Letters, Vol.79 No.4 (1999) pp.153-161, 1999.04, [URL].
427. Masato Yoshiya, Isao Tanaka, Kenji Kaneko, Hirohiko Adachi, First principles calculation of chemical shifts in ELNES/NEXAFS of titanium oxides, Journal of Physics Condensed Matter, 10.1088/0953-8984/11/16/003, 11, 16, 3217-3228, 1999.04, First principles molecular orbital calculations of three titanium oxides are made in order to quantify the absolute transition energies of ELNES/NEXAFS at the O K and Ti L2,3 edges and to clarify the origin of their chemical shifts. The absolute transition energies as well as their chemical shifts at two edges are satisfactorily reproduced using clusters composed of 24 to 63 atoms when Slater's transition state method is employed allowing temporary spin-polarization. The O K edge shows a positive shift with the increase of the formal number of d electrons per Ti ion. The shift can be mainly ascribed to the variation of the energy of the t2g-like band, although the energy of the O 1s core-orbital varies slightly. On the other hand, the Ti L2,3 edge shows negative shift, which is found to be explained by the balance of energies of the Ti 2p and the t2g-like band. The magnitude of the chemical shifts is not significantly altered by the manner of the octahedral linkage..
428. K. Kaneko, M. Yoshiya, I. Tanaka and S. Tsurekawa, Chemical bonding of oxygen in intergranular amorphous layers of high-purity beta-SiC ceramics, Acta Materialia, Vol.47 No.4 (1999) pp.1281-1287, 1999.03, [URL].
429. Kenji Kaneko, M. Yoshiya, I. Tanaka, S. Tsurekawa, Chemical bonding of oxygen in intergranular amorphous layers in high-purity β-SiC ceramics, Acta Materialia, 10.1016/S1359-6454(98)00423-6, 47, 4, 1281-1287, 1999.03, An amorphous intergranular layer, 0.4 nm thick, is found by high-resolution transmission electron microscopy of β-SiC ceramics fabricated by the HIP glass-encapsulation technique without the use of additives. The intergranular layer is found to contain oxygen, which may also be present in the SiC grains near the grain boundary. The mean composition of the intergranular layer is determined to be SiO0.10±0.01C0.93±0.04, whose C/O ratio is close to a hypothetical Si-oxycarbide stoichiometry. Electron energy loss spectroscopy shows that both the Si-L23 and O-K edges from the intergranular layer are distinctive compared to those of SiC and/or SiO2. This provides direct evidence of the presence of oxygen in a chemical environment different to that in glassy SiO2, that can also be found in the intergranular layer. First principle calculations by the DV-Xα method using an interface model cluster, satisfactorily reproduce the chemical shifts of the energy loss near edge structure (ELNES) for both the Si-L23 and O-K edges..
430. M. Kusunoki, T. Suzuki, Kenji Kaneko, M. Ito, Formation of self-aligned carbon nanotube films by surface decomposition of silicon carbide, Philosophical Magazine Letters, 10.1080/095008399177381, 79, 4, 153-161, 1999.01, A simple method of producing aligned carbon nanotube films and a mechanism for their formation are described. The alignment method is based on the self-organization by surface decomposition of a SiC wafer in a vacuum at a temperature between 1500 and 1700° C. From the results of cross-sectional observations by high-resolution transmission electron microscopy and analytical electron microscopy, the following formation mechanism is proposed: SiO gas molecules are generated by surface oxidation and graphite caps of 2-5 nm in size are formed by the bubbling of SiO gas on the surface, characterized by a (0001)SiC plane. Then carbon nanotubes grow in a vertical direction, eroding the SiC crystal during the continuous oxidation..
431. K. Kaneko T. Gemming I. Tanaka and H. Muellejans, Analytical investigation of Random Grain Boundaries of Zr doped sintered alpha-Al2O3 by transmission electron microscopy and scanning transmission electron microscopy, Philosophical Magazine A, Vol.77 No.5 (1998) pp.1255-1272, 1998.05, [URL].
432. Kenji Kaneko, T. Gemming, I. Tanaka, H. Müllejans, Analytical investigation of random grain boundaries of Zr-doped sintered α-Al2O3 by transmission electron microscopy and scanning transmission electron microscopy, Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties, 77, 5, 1255-1272, 1998.05, The effects of the Zr doping in fine-grained alumina (α-Al2O3) on fine structures are studied. The combination of high-resolution transmission electron microscopy (HRTEM) and field emission scanning transmission electron microscopy has been a powerful tool for material investigations and it was employed to investigate grain-boundary structures, chemical composition and chemical bonding of 1000 ppm Zr-doped polycrystalline α-Al2O3. HRTEM revealed that the atomic structure of grain-boundary regions was not strongly distorted from that of the surrounding bulk, α-Al2O3. It was found that there was no amorphous phase at any grain boundaries. Energy-dispersive X-ray spectroscopy (EDS) and electron-energy-loss spectroscopy in a dedicated scanning transmission electron microscope used for analytical investigations provided spatial difference information about elemental-composition since the electron probe size in the scanning transmission electron microscope is as small as 3 Å. It was shown by the EDS that Zr segregated in the grain-boundary regions with the Zr-to-Al atomic ratio of 1.6 ± 0.2%. Normalization and subtraction of the matrix spectra from the interface spectra yield grain-boundary-sensitive near-edge structure of energy-loss near-edge structure (ELNES). Similar features are found for both the O K edge and the Al L2,3 edge ELNES at the boundary. The origin of these features is ascribed to the heavily misshapen defects at the random boundary..
433. K. Kaneko, I. Tanaka and M. Yoshiya, Six-fold coordinated Si at grain boundaries of sintered a-Al2O3, Applied Physics Letters, Vol.72 No.2 (1998) pp.191-193, 1998.01, [URL].
434. T. Nagano K. Kaneko and H. Kodama, Tensile Ductility of Al-Doped beta-Silicon Carbide at Elevated Temperature, The Third Pacific Rim International Conference on Advanced Materials and Processing, Vol.2 (1998) pp.1897-1902, 1998.01.
435. K. Kaneko and I. Tanaka, Detection of sixfold co-ordinated Si at grain boundaries of sintered a-Al2O3, The Electron, (1998) pp.404-410, 1998.01.
436. Kenji Kaneko, Isao Tanaka, Masato Yoshiya, Six-fold coordinated silicon at grain boundaries in sintered α-Al2O3, Applied Physics Letters, 10.1063/1.120681, 72, 2, 191-193, 1998.01, High-resolution transmission electron microscopy (HRTEM) and analytical electron microscopy (AEM) have been carried out on Si-doped sintered α-Al2O3. HRTEM shows that there is no amorphous phase at grain boundaries. The Si-segregated boundary is found to be much more sensitive to irradiation damage than undoped Al2O3 grain boundaries. AEM with energy dispersive x-ray spectroscopy (EDS) shows the significant segregation of Si at grain boundaries, and AEM with electron energy-loss spectroscopy (EELS) reveals the existence of six-fold coordinated Si at the grain boundaries. The theoretical calculations obtained by the molecular orbital method support the data obtained by EELS..
437. K. Saitou, K. Tsuda, M. Tanaka, K. Kaneko and P. Tsai, Structural Study of an Al72Ni20Co8 Decagonal Quasicrystal by the High-Angle Annular Dark-field Method, Japanese Journal of Applied Physics, Vol.36 No.10B (1997) pp.L1400-L1402, 1997.10, [URL].
438. Koh Saitoh, Kenji Tsuda, Michiyoshi Tanaka, Kenji Kaneko, An Pang Tsai, Structural study of an Al72Ni20Co8 decagonal quasicrystal using the high-angle annular dark-field method, Japanese Journal of Applied Physics, Part 1: Regular Papers & Short Notes, 36, 10 SUPPL. B, 1997.10, High-angle annular dark-field (HAADF) images of an Al72Ni20Co8 decagonal quasicrystal have been taken for the first time. It has been found that the transition metals form pentagonal and star-shaped cluster columns with radii of about 0.4 nm. The atom-cluster columns with a 2 nm diameter of the alloy, which have been considered as the basic structural unit with decagonal symmetry so far, have been revealed to have no decagonal symmetry. These atom-cluster columns have been found to be decomposed into the pentagonal and star-shaped cluster columns, corresponding clusters existing in the Al13Fe4 monoclinic approximant. The tiling of the pentagonal and star-shaped clusters has been found to agree with the rhombic Penrose lattice for an area with a diameter greater than 50 nm..
439. D. Cherns K. Kaneko A. Hovespian and A. R. Lang, Measurement of the lattice displacement across {100} platelets in diamond by large-angle convergent-beam electron diffraction, Philosophical Magazine A, Vol.75 No.6 (1997) pp.1553-1566, 1997.06, [URL].
440. K. Kaneko, T. Gemming and I. Tanaka, Analytical Investigation of Grain Boundary of polycrystalline alumina by STEM, Inst. Phys. Conf. Ser. (EMAG 97), Vol.153 (1997) pp.307-310, 1997.01.
441. D. Cherns, Kenji Kaneko, A. Hovsepian, A. Lang, Measurement of the lattice displacement across {100} platelets in diamond by large-angle convergent-beam electron diffraction, Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties, 10.1080/01418619708223743, 75, 6, 1553-1566, 1997.01, Large-angle convergent-beam electron diffraction is used to measure the displacement across {100} (R00) platelets in an Argyle brown diamond. By examining the intersection of a series of two-beam diffraction contours g with an inclined platelet, it is shown that integral and fractional components of g.R can be separately determined. The integral part of g.R is determined by applying standard Cherns-Preston rules to the image of the bounding partial dislocation. The fractional part / of g.R is determined by comparing the rocking curve in the faulted region with two-beam dynamical simulations. It is shown that the rocking-curve asymmetry at small deviation parameters provides a simple measurement of f which is relatively unaffected by background inelastic scattering and a finite probe size. Higher-order reflections are used to improve sensitivity, giving R = 0.40±0.01. This result is compared with measurements obtained by other techniques and its significance for understanding the structure of diamond platelets is discussed..
442. K. Kaneko and D. Cherns, The use of LACBED to study matrix displacements from {100} platelets in diamond, Inst. Phys. Conf. Ser. (EMAG 95), Vol.147 (1995) pp.157-160, 1995.01.
443. K. Kaneko and A. R.Lang, A study of defects in Argyle coloured diamonds, Inst. Phys. Conf. Ser. (EMAG 95), Vol.147 (1995) pp.337-340, 1995.01.
444. F. C. Frank, J. W. Harris, K. Kaneko and A. R. Lang, Linear Decorations defining edges of an internal octahedron within a natural diamond: observation and explanation, Journal of Crystal Growth, Vol.143 No.1-2 (1994) pp.46-57, 1994.10, [URL].
445. F. C. Frank, J. W. Harris, Kenji Kaneko, A. R. Lang, Linear decorations defining edges of an internal octahedron within a natural diamond
observations and an explanation, Journal of Crystal Growth, 10.1016/0022-0248(94)90366-2, 143, 1-2, 46-57, 1994.10, A 2.13 carat weight natural diamond, a slightly flattened octahedron with roughly-pitted surfaces, exhibits an internal framework of dense black "lines" located a short distance below the present surface. Most of the lines lie closely parallel to 〈110〉 and connect up to delineate edges of an octahedron concentric with and slightly smaller than the present body. The lines are agglomerations of thin black discs (thickness too small to be measured in situ by optical microscopy), diameters ranging from 1 to 40 μm (but mainly in the 5 to 20 μm range), equantly distributed on diamond {111}, and consistent with graphite. Special optical techniques were developed for examining this specimen and they provided control of relative visibility of internal versus superficial features. Optical micrographs taken in all eight 〈111〉 directions are discussed. Synchroton X-ray topography detected the internal linear framework with good contrast, and helpfully displayed spatial relations between its segments. Findings from cathodoluminescence topography are described. An explanation of the phenomenon is outlined. It proposes a sequence of pressure and temperature conditions and of resulting stresses between diamond and encasing solid matrix whereby graphitization was caused to occur locally along edges of an octahedron, which was subsequently enclosed by further diamond growth. Implications for the origin of the edge grooves frequently exhibited by diamond octahedra are suggested..
446. K. Kaneko and A. R. Lang, CL and optical micrographic studies of Argyle Diamond, Industrial Diamond Review, Vol.53 No.6 (1993) pp.334-337, 1993.06.