Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Masashi Mukaida Last modified date:2021.08.16

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


Papers
1. M MUKAIDA, M YAMAMOTO, Y TAZOH, K KURODA, K HOHKAWA, SYNTHESIS OF SUPERCONDUCTING YBA2CU3O7-DELTA THIN-FILMS BY ELECTRON-BEAM DEPOSITION, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 27, 2, L211-L213, 1988.02.
2. K KURODA, M MUKAIDA, M YAMAMOTO, S MIYAZAWA, PREPARATION OF NEW HIGH-TC SUPERCONDUCTING OXIDE BI-SR-CA-CU-O THIN-FILM BY ELECTRON-BEAM DEPOSITION TECHNIQUE, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 27, 4, L625-L627, 1988.04.
3. K KURODA, M MUKAIDA, S MIYAZAWA, COMPOSITION DEPENDENCE AND ELECTRICAL-PROPERTIES OF TC-GREATER-THAN-100-K BISRCACUO SUPERCONDUCTING OXIDE-FILMS PREPARED BY SEQUENTIAL DEPOSITION, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 27, 11, L2230-L2232, 1988.11.
4. M MUKAIDA, K KURODA, S MIYAZAWA, HALL-COEFFICIENT OF C-AXIS ORIENTED BI-SR-CA-CU-O 107-K FILMS, APPLIED PHYSICS LETTERS, 55, 11, 1129-1131, 1989.09.
5. M MUKAIDA, S MIYAZAWA, M SASAURA, K KURODA, PREPARATION OF YBA2CU3O7-Y HIGH-TC THIN-FILMS ON NDGAO3 SUBSTRATE BY LASER ABLATION, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 29, 6, L936-L939, 1990.06.
6. M SASAURA, M MUKAIDA, S MIYAZAWA, NEW SUBSTRATE PRGAO3 FOR A HIGH-TC SUPERCONDUCTING YBA2CU3OX EPITAXIAL FILM, APPLIED PHYSICS LETTERS, 57, 25, 2728-2729, 1990.12.
7. M MUKAIDA, S MIYAZAWA, M SASAURA, SUPERCONDUCTING YBA2CU3OX THIN-FILM GROWTH ON A VICINAL SURFACE OF NDGAO3 SUBSTRATE, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 30, 8B, L1474-L1476, 1991.08, Surface morphology is observed for a superconducting YBa2Cu3O(x) (YBCO) thin film grown on a 1.7-degrees off angle vicinal surface of lattice-matched NdGaO3 substrate. Ragged step-like edges are clearly observable with exclusions in the front of the edges. The height of a step is measured to be 20 angstrom approximately 30 angstrom and is calculated from the vicinal angel and the terrace width to be 23 +/- 2 angstrom, indicating an evidence for a doubled periodicity of YBCO crystal c-axis unit length of approximately 12 angstrom..
8. J KOBAYASHI, Y TAZOH, M MUKAIDA, S MIYAZAWA, ALL HIGH-TC EPITAXIAL YBA2CU3OX/NDGAO3/YBA2CU3OX HETEROSTRUCTURES, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 185, 2039-2040, 1991.12, SIS (Superconductor/Insulator/Superconductor) structures consisting of high-Tc YBa2Cu3Ox (YBCO) require epitaxial interfaces. To devise these interfaces, we have fabricated the SIS structure using NdGaO3 lattice-matched with YBCO as a substrate and an insulating layer. SIS structures were examined by Reflection High Energy Electron Diffraction (RHEED). X-ray Reflection Diffractometry (XRD) and Scanning Electron Microscopy (SEM). Results show that all epitaxial SIS structures were successfully fabricated..
9. M MUKAIDA, S MIYAZAWA, GROWTH AND CRYSTALLOGRAPHIC ANALYSIS OF YBA2CU3OX THIN-FILMS ON NDGAO3 SUBSTRATES, JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 31, 10, 3317-3322, 1992.10, The growth and crystallographic analysis of a-axis-oriented YBa2Cu3Ox (abbreviated to YBCO) grains in c-axis-oriented films on NdGaO3 substrates is described. a-axis-oriented grains grow at high substrate temperatures and high oxygen pressures. Reflection high energy electron diffraction (RHEED) patterns and phi-scan (in-plane rotation) X-ray measurements reveal that the grains exhibit a twofold symmetry indicating independent b- and c-axis orientations in the surface plane. The in-plane orientation of a-axis-oriented grains is thought to be responsible for the rectangular surface lattice of (110) NdGaO3 substrate..
10. S MIYAZAWA, M SASAURA, M MUKAIDA, SINGLE-CRYSTAL GROWTH OF RARE-EARTH GALLATES AND EPITACTIC GROWTH NATURE OF HIGH-TC SUPERCONDUCTING YBCO THIN-FILMS ON THEM, JOURNAL OF CRYSTAL GROWTH, 128, 1-4, 704-708, 1993.03, Rare-earth gallates, NdGaO3 and PrGaO3, as substrates lattice-matched to superconducting YBCO thin films are grown using a Czochralski pulling technique. NdGaO3 Was twin-free, while PrGaO3 was badly twinned. Twinning in PrGaO3 is presumably due to the first-order phase transition below the melting temperature. On twin-free NdGaO3 substrates, the initial growth stages of YBCO ultrathin films are observed by an atomic force microscope (AFM). AFM reveals that the growth mode is of Stranski-Krastanov, showing two-dimensional lateral growth and subsequent three-dimensional island formation, where the growth unit is one or multiples of the c-axis cell length in height..
11. M MUKAIDA, S MIYAZAWA, PREFERENTIAL AXIS CONTROL OF YBA2CU3OX THIN-FILM BY QUASI-LATTICE-MATCH ENGINEERING, JOURNAL OF APPLIED PHYSICS, 74, 2, 1209-1212, 1993.07, The lowest temperature for c-axis preferred oriented thin film growth is investigated for films on different substrate materials. This temperature has a maximum when the lattice constant of the substrate matches that of YBa2Cu3Ox. This result readily explains a-axis preferred oriented film growth by the template technique. We propose quasilattice-match engineering as a technique for controlling the preferential orientation axis of a part of a YBa2Cu3Ox thin film by using a seed layer whose lattice mismatch differs from that of the substrate. The part of the YBa2Cu3Ox thin film on a PrGaO3 seed layer is a-axis oriented and the film directly deposited on a SrTiO3 substrate is c-axis oriented..
12. M MUKAIDA, S MIYAZAWA, TRANSPORT ANISOTROPY OF INPLANE C-AXIS ALIGNED ALPHA-AXIS ORIENTED YBA2CU3OX THIN-FILMS, PHYSICA B-CONDENSED MATTER, 194, 2311-2312, 1994.02, The temperature dependence of resistivity, rho(b) and rho(c), is measured for a perfectly in-plane c-axis aligned a-axis oriented YBa2Cu3Ox thin film. In-plane alignment of the film is confirmed by X-ray phi-scan (in-plane rotation) diffraction and reflection high-energy electron diffraction (RHEED) measurements. X-ray phi-scan measurements and RHEED patterns reveal that the thin film has a twofold symmetry with no 90-degrees domains, showing the c-axis for the film is aligned in-plane. Resistivity-temperature curves for both c- and b-directions show metallic behavior with a T(C) of 90.5 K. Resistivity in the c-axis direction at 290 K is 5.5 mOMEGAcm, which is about eleven times larger than that of 500 muOMEGAcm for the b-axis direction. The resistivity anisotropy is in the same order as the coherence length. The temperature differential of normalized resistivity, d(rho(T)/rho(300))/dT, in the b-axis direction (2.8 x 10(-3)/K) is 2.5 times larger than that in the c-axis direction (1.1 x 10(-3)/K). This result clearly shows that the carrier transport in the b-axis direction is more metallic than that in the c-axis direction..
13. Yasuo Tazoh, Masashi Mukaida, Shintaro Miyazawa, New Insulating Material for YBa2Cu3Ox/Insulator/YBa2Cu3Ox Tunnel Junctions, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 235-40, 3343-3344, 1994.12, BaSnO3 is proposed as a new insulating material for YBCO-SIS tunnel junctions from the viewpoint of the superconducting behavior of a layer-structured YBCO. YBCO and BaSnO3 thin films were grown in-situ by a reactive co-evaporation in oxygen radicals. XRD, AFM, and RHEED observations confirm that (001) oriented YBCO and (100) oriented BaSnO3 thin films grow epitaxially on each other. Cross-sectional TEM observations reveal that about 4 nm thick BaSnO3 thin films perfectly cover the lower YBCO thin film surface steps with a height of one unit cell length of YBCO. T-c of the lower and upper YBCO thin films is higher than 80 K..
14. S MIYAZAWA, M MUKAIDA, ATOMIC GRAPHOEPITAXY - A GROWTH-MODEL FOR C-AXIS IN-PLANE-ALIGNED, A-AXIS ORIENTED YBA2CU3OX THIN-FILMS, APPLIED PHYSICS LETTERS, 64, 16, 2160-2162, 1994.04, The simple growth model of pure a-axis-oriented YBa2Cu3Ox thin films on (100)-oriented SrLaGaO4 substrates of a K2NiF4-type structure is proposed. This is called ''atomic graphoepitaxy.'' The model is based on an atomic-scale geometry of the (100) surface of K2NiF4-type substrates, which is characterized by atomic-scale grooves made of oxygen octahedra running along the [010] direction. These grooves are assumed to act as preferential nucleation sites of c-axis in-plane-aligned, a-axis-oriented YBa2Cu3Ox. Based on this hypothesis, the pure a-axis-oriented thin films are successfully obtained on (100)-oriented Nd2CuO4 substrates of K2NiF4-type structure..
15. M Tsukada, M Mukaida, S Miyazawa, Structural and dielectric properties of Ba(Ti1-xSnx)O-3 thin films, JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 35, 9B, 4908-4912, 1996.09, Close correlation between the dielectric constant and the degree of preferential (111) orientation is found for Ba(Ti0.85Sn0.15)O-3 (BTS15) solid-solution thin films deposited on a Pt/Ti/SiO2/Si(100) substrate by pulsed laser deposition. It is shown that substrate temperature is the principal factor which determines orientation and crystalline quality of the films. Substrate temperatures higher than 700 degrees C are required to achieve (111) orientation with good crystalline quality. BTS15 films with strong (111) orientation have large dielectric constant which reaches 2500 at 22 degrees C. These films exhibit a D-E hysteresis loop, but small remanent polarization of 0.89 mu C/cm(2) and coercive field of 3.2kV/cm are obtained at 18 degrees C. Films having the composition with lower Sn ratio exhibit larger remanent polarization. Causal relationships among the dominant film orientation, crystalline quality and dielectric constant are discussed..
16. S Miyazawa, M Mukaida, Formation of stacking-faults in atomic graphoepitaxial alpha-axis YBa2Cu3Ox, thin films on (100)SrLaGaO4 substrates, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 35, 9B, L1177-L1180, 1996.09, The complicated crystalline microstructure of cards in-plane-aligned, a-axis oriented YBa2Cu3Ox thin films on K2NiF4-type (100) SrLaGaO4 substrates is discussed in relation to surface irregularities inherent in the (100) SrLaGaO4 substrate. Transmission electron microscopy reveals that interlattice planes of YBa2Cu3Ox shift by multiples of c/6 unit, resulting in anti-phase domain boundaries and stacking-faults. The formation of these defects can be correlated with the cobbled substrate surface and is modeled in terms of atomic steps on the cobbled surface based on our growth model named ''atomic graphoepitaxy''..
17. S Miyazawa, M Mukaida, M Sasaura, Thin film crystallinity and substrate materials in atomic graphoepitaxy of YBa2Cu3Ox, ACTA PHYSICA POLONICA A, 92, 1, 85-96, 1997.07, The complexity of a-/c-axis oriented growth of YBa2 Cu3Ox thin films is reviewed from the viewpoint of controlling a-axis preferred thin him growth. Perfectly c-axis in-plane-aligned a-axis oriented YBa2Cu3Ox thin films, or ''pure'' a-axis oriented films, can be grown on the (100) face of tetragonal K2NiF4-type substrates by template growth process. A new growth mechanism called atomic graphoepitaxy is presented as a growth model. Transmission electron microscopy reveals that the films on a (100) SrLaGaO4 substrate consist of domains surrounded by anti-phase and stacking-fault boundaries, This domain formation can be well explained by substrate surface irregularities inherent in the SrLaGaO4 crystal. The formation of defects in microstructures in ''pure'' a-axis oriented YBa2Cu3Ox thin films is also modeled based an our atomic graphoepitaxial growth model..
18. S Miyazawa, M Mukaida, Transmission electron microscope observations of interfaces in YBa2Cu3Ox/BaSnO3/YBa2Cu3Ox trilayers, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS, 37, 8A, L949-L952, 1998.08, A new insulating material, BaSnO3 with a relatively large mismatch to YBa2C3Ox is investigated as a barrier material in a superconductor/ insulator/ superconductor (SIS) structure. All c-axis oriented YBa2Cu3Ox/BaSnO3/YBa2Cu3Ox SIS structures are grown by an in situ sequential pulsed laser deposition technique. Transmission electron microscopy (TEM) reveals that BaSnO3 thin films cover well c-axis oriented YBa2Cu3Ox thin films. Moreover, c-axis oriented YBa2Cu3Ox thin films grow epitaxially on BaSnO3 thin films with very good wetability. The relatively large mismatch provides periodical lattice discontinuity, which is probably associated with the generation of dislocations in one third of c-axis unit of YBa2Cu3Ox thin films. This study provides guidelines for selecting insulating materials..
19. The influence of in-plane 0-45°grain boundary on microwave surface resistance of c-axis YBa2Cu3Oy films on MgO substrate (共著)
The effect of in-plane 0-45° grain boundaries on surface resistance (R s ) of c-axis YBa 2 Cu 3 O y (YBCO) films on MgO substrates is discussed. Samples that have various densities of 45° rotated grains were prepared using a self-template technique. The R s values at 22 GHz were measured by the dielectric resonator method using a cryocooler. The R s systematically changed corresponding to the amount of 0-45° grain boundaries. Conspicuous feature of the films including 0-45° grain boundaries is a large residual surface resistance. The R s of almost perfectly in-plane aligned YBCO film scaled to 10 GHz were 0.12 mΩ at 20 K and 0.67 mΩ at 77 K on the assumption of tan δ = 0, respectively..
20. New measurement technique of the surface impedance of superconductors using the probe-coupling type microstripline resonator
We have developed a probe-coupling type microstripline resonator method for accurate measurement of the surface impedance of superconductors. By this improved microstripline resonator method, the surface impedance can be measured without attaching any contacts to the film. This paper reports the accurate and reproducible measurement process of surface impedance using the probe-coupling type microstripline resonator. The surface impedance of a YBCO thin film was measured using this technique. The measured results revealed that this technique may be used for the accurate measurement of surface impedance..
21. Microwave Surface Resistance of YBCO Thin Films on Cerium Oxide Buffer
The effects of the crystallinity and surface roughness of CeOz buffer on It-plane A1}O3 substrate on the microwave surface resistance (RJ of YBBjCUjO YBCO) thin films are discussed. We estimated Rf from the transmission characteristics of the microstrip line resonator at 25 K and 6.7 GHz. X-ray diffraction (XRD) of 6-26 and -scan showed that CeO, was completely (OOl)-oriented and in-plane aligned crystal Four CeO: samples with different thicknesses were prepared nsing identical conditions except for the deposition time. The dependence of Rf on CeO, thickness was measured in the range from 10 nm to 200 nm. The value of Rt was minimum at CeO2 thickness of 100 nm. The dependence of A( vs CeO2 thickness was similar to that of the amount of a-axis domains against the thickness. The crystallinity of thin CeOj was poor because the lattice was strongly strained by A12O3. This affected the quality of the upper YBCO layer. In contrast, thick CeO2 had excellent crystallinity. However, for the thickness of more than 100 nm a drastic change in surface morphology was observed by atomic force microscopy (AFM). A number of projections appeared on the CeO,surface. These projections act as nucleation centers for the a-axis domains. © 1999 IEEE..
22. M Mukaida, Y Takano, K Chiba, T Moriya, M Kusunoki, S Ohshima, In-plane orientation control of C-axis oriented YBa2Cu3O7-delta films on MgO substrates by BaSnO3 buffer layers, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS, 38, 8B, L926-L928, 1999.08, A new BaSnO3 buffer layer is proposed for controlling the in-plane orientation of YBa2Cu3O7-delta films grown on MgO substrates. BaSnO3 buffer layers and YBa2Cu3O7-delta films are grown by pulsed laser deposition. 45 degrees grain boundaries in YBa2Cu3O7-delta films grown on MgO (001) substrates, which are fatal defects for microwave device applications, are eliminated using the BaSnO3 buffer layer. YBa2Cu3O7-delta films grown at an optimum growth temperature of 710 degrees C on BaSnO3 buffer layers on MgO (001) substrates show lower surface resistance (R-S) than those on MgO(001)substrates without BaSnO3 buffer layers..
23. In-plane orientation of C-axis oriented YBa2Cu3Ox films on MgO substrates
The appearance of 45° grain boundaries in c-axis oriented YBa2Cu3Ox films grown by pulsed laser deposition on MgO (001) substrates is discussed. X-ray φ-scan (in-plane orientation) measurements have revealed that YBa2Cu3Ox films grown at around 700°C have two types of grains with [100]Mgo ∥ [100]YBCO and [110]MgO ∥ [100]YBCO in-plane epitaxial relationships. A plausible growth model is proposed from the viewpoints of lattice matching and ionic adhesive energy. The ratio of 0° and 45° grains is found to be a function of the substrate temperature. By decreasing the substrate temperature, we obtained c-axis oriented YBa2Cu3Ox thin films with only a [100]Mgo ∥ [100]YBCO in-plane epitaxial relation. We have eliminated the 45° grain boundaries which drastically increase the surface resistance of the YBa2Cu3Ox films for microwave applications. ©1999 Publication Board, Japanese Journal of Applied Physics..
24. Effect of the CeO2 buffer layer thickness on the microwave properties of YBCO thin films
We have examined the effect of varying the CeO2 buffer layer thickness on the microwave surface resistance Rs and surface morphology of YBCO films deposited by pulsed laser deposition. Above the critical thickness value dc of CeO2 at approx. 90 nm, the surface roughness and areal density of outgrowths of the film increased significantly. The YBCO films grown on CeO2 with thickness less than dc were completely c-axis oriented and had lower c-axis lengths than those grown on CeO2 with thickness greater than dc. Rs measured via the sapphire dielectric resonator technique was significantly lower for the YBCO film grown on CeO2 with thickness less than dc. The increase in the Rs value when the buffer layer thickness is greater than dc is considered to be due to the increased surface outgrowths and presence of a-axis domains in the YBCO film. Changes in the microstructure and orientation of the YBCO films were found to be strongly influenced by the underlying CeO2 layer..
25. Effect of deposition rate on the surface morphology of CeO2 films deposited by pulsed laser deposition (共著)
We have investigated the effect of the deposition rate, as a direct function of the laser pulse repetition rate, on the surface morphology of CeO2 films deposited by the pulsed laser deposition (PLD) technique on r-cut Al2O3 (11̄02) substrates. The critical thickness is defined as the thickness before the onset of increased growth of large islands and abrupt increase in surface roughening. Two regimes of growth were found within the investigated range of deposition rate. It is found out that in the high deposition rate-regime (within 2-4 nm/min), the critical thickness is approx. 90 nm, but in the low deposition rate-regime (less than 1 nm/min), the critical thickness is shifted to approx. 40 nm. Films belonging to these two regimes of crystalline growth were found to have characteristically different formations and surface morphologies. As observed through atomic force microscopy (AFM), the surface morphology is composed of longitudinal islands forming a maze-like pattern in the high deposition rate-regime, while the characteristic morphology was composed of rounded islands in the low deposition rate-regime. Significant reduction in the areal density of large islands and characteristically smoother films was achieved using a low deposition rate..
26. A new epitaxial BaSnO3 Buffer layer for YBaCu307-δthin films on MgO substrates (共著)
45° grain boundaries, which drastically increase surface resistance (RS) in superconducting YBa2Cu3O7-δ films for microwave devices on MgO substrates, are eliminated using a new buffer layer of BaSnO3. BaSnO3 buffer layers and YBa2Cu3O7-δ films are grown by ArF pulsed laser deposition. Epitaxial relationships among BaSnO3, YBa2Cu3O7-δ and MgO are confirmed by x-ray φ-scanning. The RS values of the YBa2Cu3O7-δ films are measured using a dielectric resonator with 22 GHz TE011 mode. The epitaxial YBa2Cu3O7-δ films grown on BaSnO3 buffered MgO substrates show lower RS than YBa2Cu3O7-δ films directly grown on MgO substrates. The BaSnO3 buffer layer which enables YBa2Cu3O7-δ films to grow without 45° grain boundaries at a optimum film growth condition is attractive for microwave applications..
27. M Mukaida, S Oikawa, M Kusunoki, S Ohshima, High-temperature resistance of YBa2Cu3O7-delta films under various oxygen pressures, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 13, 9, L5-L9, 2000.09, The electrical resistance of a c-axis-oriented YBa2Cu3O7-delta film is measured at elevated temperatures, under various values of oxygen pressure. The resistance shows a monotonic increase with substrate temperature up to around 450 degrees C, indicating little oxygen out-diffusion. Above this temperature, the rapid increase of the electrical resistance shows out-diffusion of oxygen from the film. As the temperature is increased, an abrupt drop occurs above a certain temperature (T-m) where the resistance indicates its highest value. T-m has an oxygen pressure dependence, which is similar to the oxygen pressure dependence of the orthorhombic-to-tetragonal transition line in an oxygen pressure-inverse of temperature phase diagram of YBa2Cu3O7-delta. From the observation of surface morphologies, the T-m is thought to be a sort of melting temperature where a partial melting of the YBa2Cu3O7-delta film occurs..
28. S Ohshima, KD Develos, K Ehata, MI Ali, M Mukaida, Fabrication of low surface resistance YBCO films and its application to microwave devices, PHYSICA C, 335, 1-4, 207-213, 2000.06, We have examined a fabrication process of low surface resistance (Rs) YBa2Cu3O7-delta (YBCO) films on CeO2/Al2O3 substrates by a laser ablation technique. The surface morphology of CeO2 films depended on the film thickness of CeO2. A critical value of the CeO2 film thickness at similar to 90 nm was found above which the surface roughness increased abruptly. The Rs of YBCO films also depended on the surface morphology of CeO2 films. The Rs value of YBCO films on thinner CeO2 films (< 90 nm) was quite smaller than that of YBCO films on thicker CeO2 films (> 90 nm). We have also examined the high-temperature superconducting (HTS) antenna as one of the HTS passive devices, and measured the power handling capability. The compact cooling system for HTS patch antenna was constructed. (C) 2000 Elsevier Science B.V. All rights reserved..
29. S Ohshima, Y Takano, M Mukaida, M Kusunoki, K Ehata, K Chiba, T Suzuki, M Inadomaru, Fabrication of low Rs YBCO films and its application to patch antennas, PHYSICA C, 341, 2565-2568, 2000.11, We have examined that how to reduce the surface resistance, Rs of YBCO films, and found that control of the in-plane alignment of the YBCO films was very important to realize that. The in-plane alignment of the YBCO films on MgO substrates could be controlled by the BaSnO3(BSO) buffer layers, and self-template method. We also examined YBCO patch antenna and its compact cooling system. The compact cooling system was easy to keep YBCO patch antennas in the superconducting state..
30. Elimination of α-axis growth in YBa2Cu3O7-8 films on CeO2-buffered Al2O3
The elimination of α-axis orientation in YBa2Cu3O7-8 (YBCO) films grown on CeO2-buffered A12O3 for microwave devices was achieved through a two-step deposition process performed at different temperatures. The growth of α-axis-oriented YBCO film was considered to be due to the impediment of the adatom mobility by the surface roughness of the underlying buffer layer. For the initial layer, the deposition was carried out at a high temperature to increase surface mobility. Next, the deposition was performed at a lower temperature as necessary for optimum α-axis-oriented growth. By this method, only a α-axis-oriented film was obtained. The characteristic surface resistance Rs(T) values for this film were significantly lower than those with mixed c-and α-axis orientations. © 2000 Publication Board, Japanese Journal of Applied Physics..
31. Surface Resistance Measurement of Superconducting Thin Film Using Probe-Coupling Type Microstrip Line Resonator
超伝導マイクロ波受動デバイスを設計するためには, 超伝導薄膜の表面抵抗を考慮する必要がある.このため, 超伝導薄膜の表面抵抗の高精度測定法の確立が望まれている.本論文では, 超伝導薄膜の表面抵抗の測定法としてプローブ結合型マイクロストリップ線路共振器法を提案する.共振器法では, 表面抵抗は共振器の無負荷Q, Quから計算される.したがって, マイクロストリップ線路共振器法により超伝導薄膜の表面抵抗を正確に求めるためには, 共振器のQuを高精度測定する技術の確立が重要となる.プローブ結合型マイクロストリップ線路共振器法により金属と超伝導薄膜から作製した共振器のQu測定を行い, プローブ結合型マイクロストリップ線路共振器法によるQu測定の測定精度と, 超伝導薄膜の表面抵抗測定の再現性について述べる..
32. The effect of lattice matching between buffer layer and YBa2Cu3O7-δ thin film on in-plane alignment of C-axis oriented thin films
The effect of lattice matching between YBa2Cu3O7-δ (YBCO) films and buffer layers as well as between buffer layers and MgO substrates have been discussed from viewpoints of crystalline, critical temperature and surface resistance of YBCO films. SrSnO3(SSO) as well as BaSnO3 (BSO) were used as buffer materials. SSO has closer lattice constant to YBCO than BSO. YBCO films were grown on these materials at the optimal growth temperature by pulse laser deposition. The FWHM of φ-scan (102) plane of YBCO films on SSO buffer layers was smaller than that of YBCO films on BSO buffer layers. However the values of FWHM of 005 rocking-curve of YBCO films on BSO buffer layer were smaller than that of YBCO films on SSO buffer layer. The difference of surface resistance between YBCO film on BSO buffer layer and YBCO film on SSO buffer layer was very small indicating superconducting properties are not mainly governed by lattice mismatch at this region. We obtained the same values for c-axis length and critical temperature in YBCO films on these materials..
33. Relationship between the surface resistance and crystal orientation of YBa2Cu3O7-δ thin film
We have examined the relationship between in-plane orientation, grain size, fluctuation of grain axis and surface resistance of YBa2Cu3O7-δ (YBCO) films. The surface resistance of YBCO films with a mixture of (100) and (110) in-plane grains was larger than that of the films with perfect in-plane orientation. The behavior of surface resistance could be explained by the degree of grain boundaries of (100) and (110) in-plane orientation. The surface resistance of YBCO films was proportion to the fluctuation of grain axis. It was also proven that surface resistance of high-temperature superconductors is affected by the critical current..
34. New surface resistance measurement technique of high-temperature superconductors using a probe coupling microstrip line resonator
We have developed a new surface resistance (Rs) measurement technique of high-temperature superconductors using a probe coupling microstrip line resonator. In this technique, the probe coupling method is used to measure the Rs of superconductors without attaching any contacts to the superconductors. This paper reports the measurement process of the Rs of a superconducting fine-wire using this technique. The quality factors of the copper wires, gold fine-wire and the Bi-Sr-Ca-Cu-O whisker crystal were measured by the probe coupling resonator method. The measurement results revealed that this technique is feasible for the Rs measurement of the superconducting fine-wire..
35. Miniaturized cooling systems for HTS antennas
Two types of miniaturized cooling systems for High-Temperature Superconducting (HTS) antennas were designed and built. In this paper, details of these systems, measured and simulated properties of patch antennas installed in these systems, and results of a seal-off trial for 1 month are reported. Both the systems had portable size and weight and could cool the HTS devices. When a patch antenna with resonant frequency of 4.9 GHz was installed in the 1st cooling system, the radiation pattern of the antenna was strongly focused in the forward direction. This is because the vacuum chamber in which the antenna was packaged influenced the microwaves radiated from the antenna. Due to this effect, the directive gain of the antenna was enhanced by 11.2 dB. In the 2nd system, a seal-off trial was carried out to investigate the airtight property that is necessary for thermal isolation. The temperature of the sample stage could be kept under the critical temperature of YBCO for 1 month without continuous vacuum pumping. The cooling systems developed in this work are expected to promote the practical use of HTS antennas..
36. K Develos, H Yamasaki, A Sawa, Y Nakagawa, S Ohshima, M Mukaida, Microstructure of YBa2Cu3O7-y films on CeO2-buffered Al2O3, PHYSICA C, 357, 1353-1357, 2001.08, We investigated the microstructure of epitaxial c-axis oriented YBCO films laser-deposited onto CeO2-buffered Al2O3 substrates. Using transmission electron microscopy (TEM), scanning electron microscopy and Auger electron spectroscopy, we have identified the majority of outgrowths which are spherical or polygonal in shape, with sizes ranging from 0.1 to 0.5 mum. as having the same composition as that of the YBCO matrix. Another type of outgrowth with irregular shapes and sizes ranging from 0.5 to 1.0 mum was also found to have a composition of BaCuO2 or CuO. Combined scanning transmission electron microscopy and selective area electron diffraction measurements identified the former as slightly misaligned YBCO. Although there is a large number of surface outgrowths in the YBCO film, the critical current density J(c) as calculated from hysteretic magnetization measurements is relatively high, where J(c) similar to 1.7 x 10(6) A cm(-2) at 77 K. (C) 2001 Elsevier Science B.V. All rights reserved..
37. Ln dependence in Ln2CuO4 buffer layers of c-axis in-plane aligned a-axis oriented YBa2Cu3O7-δ thin film growth
Lanthanide (Ln) atom in Ln2CuO4 buffer layer dependence of c-axis in-plane aligned a-axis oriented YBa2Cu3O7-δ (YBCO) thin film growth is discussed and preferred orientation growth model of a bc-plane matched growth model is proposed. The c-axis in-plane aligned a-axis oriented YBCO thin films are very attractive from both the researches on the origin of high Tc superconductors and microelectronics device applications. However the c-axis in-plane aligned a-axis oriented films are difficult to grow. We have been proposing Ln2CuO4 buffer layers for the c-axis in-plane aligned a-axis oriented YBCO thin film growth. We have examined various Ln atoms in Ln2CuO4 buffer layers for the growth of YBCO thin films by pulsed laser deposition. From a lattice matching point of view, a Tb2CuO4 buffer layer is the best one for the c-axis in-plane aligned a-axis oriented YBCO thin films. However the result shows that the Nd2CuO4 and Tb2CuO4 buffer layer causes YBCO thin films with c-axis oriented portion about 35% and 32%, by X-ray diffraction peaks, which is much larger than those on Gd2CuO4 buffer layers (7.4%). The most promising Ln atom in Ln2CuO4 buffer layers for the growth of the c-axis in-plane aligned a-axis oriented YBCO thin films so far is Gd2CuO4 buffer layers or Eu2CuO4 buffer layers. © 2001 Elsevier Science B.V. All rights reserved..
38. Development of a miniaturized cooling system for HTS antennas and its seal-off property
Measured results and discussion on vacuum seal-off property of a cooling system for high-temperature superconducting antennas are reported. The cooling system was designed and fabricated and its cryogenic packaging was investigated. Vacuum seal-off tests were performed and high vacuum for thermal isolation could be kept for 25 days. On the cold stage of the system, some kinds of gas, including H2O and CO2, were adsorbed on a cold stage. © 2001 Elsevier Science B.V. All rights reserved..
39. Design of Cross-coupled Microstrip Bandpass Filter
High-temperature superconducting microwave filters were designed for the W-CDMA communication system. Frequency responses of the filters were calculated by the electromagnetic simulator "Sonnet-em". A cross-coupled 8-pole microstrip line filter shows 1.949 GHz of center frequency and 1.04% of transmission fractional bandwidth on the LaAlO3, and 1.950 GHz of center frequency and 1.02% of transmission fractional bandwidth on the Al2O3. © 2001 Elsevier Science B.V. All rights reserved..
40. Critical thickness of BaSnO3 buffer layer for YBa2Cu3O7-δ thin films on MgO substrates
The critical thickness of BaSnO3 (BSO) buffer layer for YBa2Cu3O7-δ (YBCO) thin films on MgO substrate is discussed from viewpoints of the in-plane orientation and critical temperature. Thin films are grown by changing the thickness of BSO buffer layers at optimal growth temperature of YBCO films by pulse laser deposition. We are able to control the in-plane orientation of YBCO films with the BSO buffer layers thicker than 2 nm. This result indicates that BSO buffer layers can control the in-plane orientation of YBCO with a thickness less than the other buffer materials reported so far..
41. The correlation of the critical current density and surface resistance of YBa2Cu3O7 thin films
We have examined the correlation between the critical current density (Jc) and the surface resistance (R(s)) of an YBa2Cu3O7-δ (YBCO) thin film. YBCO films were prepared in an inductively coupled plasma sputtering system on MgO and BSO/MgO substrates. BaSnO3 (BSO) was used as a buffer material for the MgO substrates. Jc was determined by magnetic measurements, and Rs was measured using a sapphire rod resonator method. The correlation of critical current and surface resistance has been reported previously, however, there is few researches in which a systematic correlation of Rs and Jc using the same sample has been done. To begin with, we measured Rs by the dielectric resonator method, and next, Jc was measured using the magnetic field method. As a result, it was proven that there was a strong correlation between Rs and Jc. We found that the relationship between Jc and Rs (at 22 GHz) could be expressed by the following equation, Rs = 2.0 × 107Jc -1, where the unit of R(s) is the ohm, and the unit of Jc is A/m2. It was found that the relation was applicable in a wide temperature range under Tc. The value of the surface resistance can be estimated, if an accurate critical current is obtained. © 2002 Elsevier Science B.V. All rights reserved..
42. Observation of vortex distribution in YBCO-QMG samples and YBCO thin films
We have examined vortex distribution of YBa2Cu3O7-δ (YBCO, Y-123) films and YBCO-QMG samples. The vortices were observed by the Bitter method using the decoration of the fine magnetic particles. Observation of vortex distribution was done in the temperature range between 25 and 90 K in the magnetic field range between 0 and 10 mT. We found that vortices of YBCO films and YBCO-QMG samples did not move at 25 K and moved slightly at 75 K, and the interface of the Y2BaCuO5 (Y-211) and Y-123 phases of the YBCO-QMG sample works as pinning center. © 2002 Elsevier Science B.V. All rights reserved..
43. Dielectric Loss Tangent of Sapphire Single Crystal Produced by Edge-defined Film-fed Growth Method
We investigated the dielectric loss tangent (tan δ) of sapphire single crystals produced by edge-defined film-fed growth (EFG) method using a dielectric resonator with YBa2Cu3Oy (YBCO) films. Surface resistance (Rs) of the YBCO film was low enough to obtain high resolution of tan δ measurement. For comparison, tan δ of the sapphire prepared by the Czochralsky (Cz) method was also evaluated. Measurements of 14 sapphire rods showed that EFG sapphire tends to have lower tan δ than Cz sapphire, while defects in Cz crystal were 1/14-1/2 less than that in EFG crystal. It means that the number of defects does not influence tan δ, if the density of defects is within the order of 104/cm2. In most EFG sapphire the value of tan δ at 30 K was estimated to be <1.0 × 10-7. It is usable for Rs measurement of high critical temperature superconducting materials. © 2002 Elsevier Science B.V. All rights reserved..
44. Y Nakamura, S Kudo, M Mukaida, S Ohshima, Crystallinity of YBCO thin films on an MgO substrate using an amorphous buffer layer deposited at a low temperature, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 378, 1241-1245, 2002.10, We have investigated crystallinity of YBCO films on an MgO substrate using an amorphous buffer layer. The evaluated films are obtained as follows: an amorphous YBCO buffer layer is deposited on the MgO substrate at a low temperature (200 degreesC); and then, an amorphous buffer layer is crystallized by the thermal annealing at a high temperature from 910 to 1030 degreesC; finally, main YBCO film is grown on the crystalline YBCO buffer layer over the MgO substrate. A significant improvement in the crystalline quality of the YBCO films was achieved, when amorphous buffer layers of 100 nm in thickness were crystallized by annealing temperature 950 degreesC and then annealing is continued for 1 h in air atmosphere. We confirmed that YBCO films grown on a well-crystallized buffer layer had better crystallinity than ones on bare MgO substrate, which has substantially large lattice mismatch. (C) 2002 Elsevier Science B.V. All rights reserved..
45. Control of grain size by initial growth stage of YBCO thin films
A grain size control technology will be described. YBa2Cu3O7-δ thin films are grown by a pulsed laser deposition method in 400 mTorr oxygen atmosphere. The films are grown by a self-template method with various self-template growth temperatures. However the temperature of the main YBa2Cu3O7-δ layer was fixed. Grain size of YBa2Cu3O7-δ thin films on MgO substrates are observed by atomic force microscope. Mean diameter of grains are calculated by the number of grains in scanned area of 1 × 1 μm2. The mean diameters are 2.49 × 102, 2.89 × 102, 4.047 × 102 and 4.192 × 102 nm for films with an initial layer growth temperature of 670, 690, 714 and 730 °C, respectively. Grain size is found to depend on the initial growth stage of the YBa2Cu3O7-δ thin film growth. These grain sizes have a strong relationship with the inverse of substrate temperature indicating thermally excited migration of YBa2Cu3O7-δ nuclei. It is also clarified that migration length of YBa2Cu3O7-δ nucleus is longer on an YBa2Cu3O7-δ films than on MgO substrates. © 2002 Elsevier Science B.V. All rights reserved..
46. Surface resistance measurement of superconducting thin film using probe-coupling-type microstrip line resonator
To design superconducting microwave receivers, the surface resistance of the superconducting thin film must be considered. Therefore, a highly accurate technique for measuring the surface resistance of superconducting thin films should be established. In this paper, we propose a probe-coupled microstrip line resonator as a technique for measuring the surface resistance of superconducting thin films. In the resonator technique, the surface resistance is calculated from Qu, the unloaded Q, of the resonator. Since the microstrip line resonator searches for an accurate surface resistance of the superconducting thin film, establishing a technique that accurately determines the Qu of the resonator is crucial. We measure the Qu values of resonators fabricated from metal and superconducting thin film by a probe-coupled microstrip line resonator and describe the accuracy of Qu measurement by the probe-coupled micro-strip line resonator and the repeatability of the surface resistance measurement of a superconducting thin film..
47. Rs measurement of HTS films in millimeter wave region using dielectric resonator method
The parallel plate dielectric resonator was applied to surface resistance (Rs) measurement of high temperature superconducting films with small area for the purpose of material research in early stage. Using 38 GHz resonance of TE013 mode, available measurement area in the film was diameter of 9 mm. From the theoretical calculation, the measurement at higher frequency had an advantage of less error in Rs that is caused by dielectric loss tangent (tan δ). The effect of dielectric loss is negligible at 38 GHz even using a sapphire with order of 10-7 of tan δ. In lower Rs region, Rs values of YBa 2Cu3Oy that were measured at 38 GHz agreed well with that of standard measurement method at 22 GHz. However the difference of Rs between two methods became larger with increase of R s. It is owing to poor signal to noise ratio at higher frequency. © 2003 Elsevier B.V. All rights reserved..
48. Fabrication and characterization of a CeO2 buffer layer on c-plane and tilt-c-plane sapphire substrates
We have examined in-plane orientation of CeO2 buffer layers on c-plane and tilt-c-plane sapphire substrates. The tilt angles are 5°, 10° and 15°, which are defined as the angles between the c-plane and the surface planes of the sapphire substrates (called 5°, 10°, 15° tilt-c-plane substrates). The films were prepared by inductively coupled plasma sputtering. The in-plane orientation of the films was measured using X-ray φ-scan. φ-scan peaks of films fabricated on c-plane substrates appeared every nπ/6 or nπ/12 (n: integer), showing 12-fold or 24-fold symmetry. The in-plane orientation is influenced by the hexagonal symmetry of the sapphire c-plane. The degree of film orientation depends on the substrate temperature during preparation. On the other hand, we found weak 4-fold symmetry for films fabricated on 10° and 15° tilt-c-plane substrates. This suggests that we can obtain CeO2 films with perfect 4-fold symmetry on tilt-c-plane sapphire substrates. © 2003 Elsevier B.V. All rights reserved..
49. Y Nakamura, S Kudo, M Mukaida, S Ohshima, Dependence of crystalline orientation on film thickness of sputtered YBa2Cu3O7-x on an MgO substrate, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/S0921-4534(03)00777-9, 392, 1276-1280, 2003.10, We have systematically investigated dependence of crystalline orientation on film thickness of sputtered YBa2Cu3O7-x (YBCO) on an MgO substrate by the X-ray diffraction (XRD) method, the phi diffraction method and atomic force microscope (AFM). From examination of crystalline orientation by XRD method and in-plane orientation by the phi diffraction method, for thinner film below about 500 nm, the YBCO film is oriented with the c-axis perpendicular to the MgO substrate surface. For thicker film above about 500 nm, the c-axis oriented grains in the YBCO film vanish entirely and the a-axis oriented grains are formed. The rectangular images of a-axis oriented grains are also observed on the surface by AFM. We found that the crystalline orientation change drastically from c-axis oriented films to a-axis oriented films with increasing film thickness. (C) 2003 Elsevier B.V. All rights reserved..
50. Demonstration of surface resistance mapping of large-area HTS films using the dielectric resonator method
A scanning mapping technique of surface resistance (Rs) using the sapphire dielectric resonator was developed and demonstrated for a 3-inch-diameter YBa2Cu3Oy film. The area of the 3-inch film was divided by 5 × 5 mm grid for scan, resulting in 101 measurement points. Values of Rs in the film varied from 2.9 to 3.8 mΩ at 22 GHz and 77 K. The distribution of Rs corresponded to that of the critical current density. Sampling of quality factors at each point was performed using non-contact measurement between film and sapphire. Since the airtight chamber was filled with dry N2 gas to avoid film degradation by frost and water during the warming process, perfect non-destructive measurement is realized. Fluctuation of distance between the surface of film and dielectric rod was monitored by resonance frequency. Errors in Rs caused by the fluctuation were calculated within ±0.01 mΩ. Furthermore, the system could detect a small (0.3 mm × 0.5 mm) scratch defect as well as the gradient of film thickness on Ag film. This technique is effective for inspection of large-area high temperature superconducting films for microwave applications. © 2002 Elsevier Science B.V. All rights reserved..
51. Correlation between vortex distribution and temperature in YBCO films and YBCO-QMG samples
We observed vortices with a modified Bitter method by evaporating nickel as the medium of decoration, in film and QMG (which are made with the quench-and-melt-growth method) YBa2Cu3 (YBCO) samples. The temperature range of observation was from 25 K to 90 K, and the external magnetic field was 2 ml. Consequently, we found that the vortex structures of these samples were stable from 25 K to near the critical temperature (∼90 K). The density of vortex was almost three times larger than that estimated from the external magnetic field. This suggests that the vortex motion may be hopping during nickel evaporation..
52. M. Ito, Y.Yoshida, Y. Ichino, M. Miura, Y. Takai, K.Matsumoto, M.Mukaida, S.Horii, A.Ichinose, 磁場中高J_c線材を目指したREBa_2Cu_3O_y薄膜の作製, 低温工学 = Journal of the Cryogenic Society of Japan, 10.2221/jcsj.39.523, 39, 11, 523-528, 2004.11.
53. Improvement of Superconducting Filter Properties using Sapphire Rod Trimming.
54. A Saito, H Shimakage, A Kawakami, Z Wang, K Kuroda, H Abe, M Naito, WJ Moon, K Kaneko, M 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, 1366-1370, 2004.10, As-grown MgB2 thin films were deposited on r-plane (1 1 2) and c-plane (0 0 1) 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, p(40 K) about 50 muOmega cm, were lower than that on the r-plane sapphire substrates, p(40 K) about 300 muOmega cm. Standard theta/2theta 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 MgB2 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. (C) 2004 Elsevier B.V. All rights reserved..
55. Surface resistance of YBa2Cu3O7-δ thin films on MgO lattice-matched BaZrO3 buffer layers
The growth and characterization of a BaZrO3 buffer layer for controlling the in-plane orientation of YBa2Cu3O7-δ films grown on MgO substrates is described. BaZrO3 buffer layers and YBa2Cu3O7-δ films are grown by pulsed laser deposition. 45° grain boundaries typically exist in YBa2Cu3O7-δ films grown on MgO(001) substrates; these are fatal defects for microwave device applications and are eliminated using the BaZrO3 buffer layer. The preferred orientation and in-plane orientation with respect to the MgO substrates are estimated for MgO lattice-matched BaZrO3 buffer layers grown on MgO substrates. YBa2Cu3O7-δ films grown at an optimum growth temperature of 710°C on BaZrO3 buffer layers on MgO(001) substrates show a lower surface resistance (RS) than those on MgO(001) substrates without BaZrO3 buffer layers..
56. Y Shingai, M Mukaida, K Matsumoto, Y Yoshida, A Ichinose, S Horii, A Saito, S Ohshima, Selective preferred orientation control of YBa2Cu3O7-delta films on a substrate, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2003.12.105, 412, 1296-1300, 2004.10, We discuss selective preferred orientation control of YBa2Cu3O7-delta films on a substrate. c-Axis oriented YBa2Cu3O7-delta films grow on the region without buffer layer. On the other hand a-axis oriented YBa2Cu3O7-delta films grow on the region with the buffer layer in spite of the same growth temperature and oxygen pressure. Crystalline orientation, surface morphology and transport properties along the b-axis of the a-axis oriented films will be also discussed. (C) 2004 Elsevier B.V. All rights reserved..
57. A Ichinose, Y Yamamoto, M Mukaida, A Kikuchi, K Tachikawa, S Akita, K Inoue, K Matsumoto, Y Yoshida, S Horii, Preparation of YBa2Cu3O7-x films on cap-layer-buffered MgO substrates using precursor films deposited from Y, BaF2 and Cu, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2004.02.225, 412, 1321-1325, 2004.10, YBa2Cu3O7-x (YBCO) is prepared by low-oxygen-pressure annealing of precursor films which are deposited from Y, BaF2, and Cu sources at room temperature. In the annealing process, pure oxygen gas is introduced into the reaction chamber. The other gases, for example, water vapor or nitrogen gas, are not intentionally introduced. We previously reported that it is difficult to control the in-plane alignment YBCO films on MgO substrates. Therefore, a single cap layer (BaSnO3) or double cap layers (CeO2/BaSnO3) are deposited on the MgO substrate. Subsequently, the YBCO films are prepared on the cap-layer-buffered MgO substrates. We evaluated the crystallinity and the film growth of the YBCO films on single-cap-layer-buffered and double-cap-layer-buffered MgO substrates. (C) 2004 Elsevier B.V. All rights reserved..
58. S Horii, M Mukaida, K Matsumoto, T Ohazama, A Ichinose, Y Yoshida, J Shimoyama, K Kishio, Post-annealing effects of superconducting properties on ErBa2Cu3Oy films fabricated by pulsed laser deposition, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2004.01.165, 412, 1306-1309, 2004.10, We report oxygen post-annealing effects of superconducting properties on ErBa2Cu3O, thin films fabricated by a pulsed laser deposition (PLD) method. Critical current densities were dramatically enhanced by an oxygen postannealing process at temperature range of 350-500 degreesC in comparison with that of the as-deposited film (similar to0.3 MA/cm(2)). Even in REBa2Cu3Oy films grown by a non-equilibrium process such as the PLD method, the oxygen post-annealing process is crucially effective for enhancement of critical current properties, which is suggesting that the oxygen annealing is a practical process for improvement of critical current of PLD-REBa2Cu3Oy, coated conductors. (C) 2004 Elsevier B.V. All rights reserved..
59. M Itoh, Y Yoshida, Y Ichino, M Miura, Y Takai, K Matsumoto, A Ichinose, M Mukaida, S Horii, Low temperature growth of high-J(c) Sm1+xBa2-xCu3Oy films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2003.12.096, 412, 833-837, 2004.10, We fabricated Sm1+xBa2-xCu3Oy (SmBCO) films on a c-axis oriented thin SmBCO seed layer by low temperature growth technique. The orientation of the film without seed layer changed from c-axis to a-axis as decrease of substrate temperature (T-s), whereas the SmBCO film with seed layer showed the complete c-axis orientation at low-T-s. This orientation mechanism was explained in view of adatom surface migration. In addition, the J(c) value of the film on seed layer increased with decreasing T-s. From XRD phi-scan measurement, it is found that in-plane alignment of SmBCO film was improved by decreasing T-s. We considered that this behavior in high J(c) SmBCO films was ascribed to improved in-plane alignment. (C) 2004 Published by Elsevier B.V..
60. T Ohazama, M Mukaida, A Ichinose, K Matsumoto, Y Yoshida, S Horii, A Saito, S Ohshima, Growth of high-quality ErBa2Cu3O7-delta thin films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2004.02.226, 412, 1301-1305, 2004.10, ErBa2Cu3O7-delta thin films are grown by pulsed laser deposition (PLD). Using a SrTiO3 as a lattice matched substrate. In the film growth, the substrate temperature is varied from 720 to 780 degreesC. From X-ray diffraction (XRD) patterns, only the 00/ reflections from the ErBa2Cu3O7-delta films are observed. The average of the c-axis length of the other films is 11.6875 Angstrom. ErBa2Cu3O7-delta film grown at 735 degreesC is excellent in the crystallinity, while the intensity of 0 0 1 peaks of the film grown at more than 780 degreesC obviously weakened. The zero resistance T-c is 90.5 K. Superconducting transition width is 1.5 K. Large and flat grains are observed by atomic force microscopy (AFM) at the surface of the film. From the scanning electron microscope (SEM) image, we confirmed some grains with the size of approximately 200 nm in diameter on the ErBa2Cu3O7-delta thin film. We observe the interface of ErBa2Cu3O7-delta, and substrate clearly by transmission electron microscopy (TEM) measurements. (C) 2004 Elsevier B.V. All rights reserved..
61. T Horide, K Matsumoto, K Osamura, A Ichinose, M Mukaida, Y Yoshida, S Horii, Flux pinning properties of YBCO thin films deposited on SrTiO3(100) and MgO(100) substrates, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2004.03.251, 412, 1291-1295, 2004.10, For applications of YBa2Cu3O7-x, (YBCO) thin films, the critical current density (J(c)) should be improved by introducing pinning centers into YBCO thin films. We prepared YBCO films on SrTiO3(1 0 0) and MgO(1 0 0) substrates by means of pulsed laser deposition in order to study the flux pinning properties of the films. The field angle dependence of J(c)(theta,B) measured at 77 K, where theta is the angle between magnetic field direction and film surface direction, was analyzed by the normalized J(c)(theta,B) and the peak component of J(c)(theta,B). We discussed the effects of substrate materials and deposition conditions on the flux pinning behaviors of the YBCO films. (C) 2004 Elsevier B.V. All rights reserved..
62. Y Yamamoto, M Mukaida, A Ichinose, K Matsumoto, Y Yoshida, S Horii, A Saito, S Ohshima, Evaluation of buffer materials for fluorine contained solid phase epitaxy of 123 films on MgO substrates, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2003.12.103, 412, 1316-1320, 2004.10, Recently solid phase epitaxial YBa2Cu3O7-delta films such as metal organic deposition using trifluoroacetate (TFA-MOD) technique, chemical solution-based coating pyrolysis, and BaF2 ex situ post reaction process have been improving their crystalline quality. In order to grow thick films, larger thermal expansion coefficient substrates than that of YBCO are preferable. From the viewpoint of thermal expansion coefficient, MgO is a promising substrate. However, it is difficult for solid phase epitaxial YBa2Cu3O7-delta films to grow directly on the MgO substrate, because fluorine reacts with Mg in the substrate. Therefore we evaluate buffer layer materials to protect MgO substrates against fluorine. Buffer layer are grown by pulsed laser deposition at around 730 degreesC on polished MgO substrates. Thin CeO2 buffer layers are difficult to grow directly on the MgO substrates. However, CeO2-capped double buffer layers grow epitaxially on MgO substrates. The examined materials for double buffer layers are CeO2/SrSnO3, CeO2/BaSnO3 and CeO2/BaZrO3. Crystallinity of the buffer layers are characterized by X-ray diffraction (XRD) theta-2theta-scans and XRD phi-scans. From XRD phi-2phi-scans patterns crystallinity of the CeO2 on BaSnO3 is higher than those of the others. From XRD phi-scans patterns, all of these buffer layers were the perfect in-plane alignment. The intensity of CeO2 film on BaSnO3 was the highest in all films. Surface morphologies are observed by AFM. From AFM observation, it was demonstrated that the surface of CeO2 film on BaSnO3 was smooth. We confirmed that CeO2 film grown on a BaSnO3 buffer layer crystallized better than others. (C) 2004 Elsevier B.V. All rights reserved..
63. S Horii, A Ichinose, M Mukaida, K Matsumoto, T Ohazama, Y Yoshida, J Shimoyama, K Kishio, Enhancement of critical current density in ErBa(2)Cu(3)Oy thin films by post-annealing, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 10.1143/JJAP.43.L1223, 43, 9A-B, L1223-L1225, 2004.09, We report a remarkable increase in critical current density (J(c)) by oxygen post-annealing for only a few tens of minutes in ErBa2Cu3Oy films fabricated at two different pulsed-laser-deposition (PLD) temperatures of 720degreesC and 760degreesC. The J(c) of these films were obviously enhanced to more than 1 MA(.)cm(-2) in the annealing temperature range of 350degreesC-500degreesC in comparison with those of the as-deposited films (0.3-0.5 MA(.)cm(-2)). Even in a nonequilibrium process such as the PLD method, the homogenization of oxygen contents in films is crucial for enhancement of the films' critical current properties, which suggests that oxygen post-annealing is a practical process for improvement of critical current of PLD-REBa2Cu3Oy coated conductors..
64. K Matsumoto, T Horide, K Osamura, M Mukaida, Y Yoshida, A Ichinose, S Horii, Enhancement of critical current density of YBCO films by introduction of artificial pinning centers due to the distributed nano-scaled Y2O3 islands on substrates, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2004.01.157, 412, 1267-1271, 2004.10, We introduced high-density extended crystalline defects, which result in artificial pinning centers of the quantized vortices, into c-axis oriented YBa2Cu3O7-x, (YBCO) films. The crystalline defects created perpendicular to the film surface were derived, during the film deposition process, by the distributed nano-sized Y2O3 islands prepared on SrTiO3 (1 0 0) substrates. The Y2O3 nano-islands were approximately 3 urn in height and 25 nm in diameter and the density was controlled from about 89 to 212 mum(-2) by choosing the Y2O3 deposition condition. J(c)s of YBCO films grown on SrTiO3 substrates with the extended defects were increased by about 150% higher than those of YBCO films without the defects. (C) 2004 Elsevier B.V. All rights reserved..
65. Y Nakamura, Y Isozaki, M Miura, T Kuroiwa, Y Yoshida, K Matsumoto, A Ichinose, S Horii, M Mukaida, S Ohshima, YBCO thin films on TiO2 buffer layer deposited by RF magnetron sputtering, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 10.1109/TASC.2005.84871, 15, 2, 3028-3030, 2005.06, Rutile structure TiO2 buffer layers and YBa2Cu3O7-x (YBCO) thin films have been deposited on (100) MgO substrates by RF magnetron sputtering. It was found that, high quality c-axis oriented YBCO thin films could be obtained on MgO with very thin (110) oriented rutile structure TiO2 buffer layers. The crystal structure of TiO2 thin films changed from (100) oriented anatase structure TiO2 to (110) oriented rutile structure TiO2 with increasing substrate temperature. The (110) oriented rutile structure TiO2 thin films deposited with the optimal deposition condition had smooth surfaces. YBCO thin films on (110) oriented rutile structure TiO2 buffer layers had better crystallinity and surface flatness than YBCO thin films deposited on bare MgO substrates..
66. S Horii, M Mukaida, Y Ichino, K Matsumoto, T Ohazama, A Ichinose, Y Yoshida, J Shimoyama, K Kishio, Oxygen post-annealing effects on critical current properties of PLD-ErBa2Cu30Oy films grown at several substrate temperatures, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2005.03.038, 426, 1015-1020, 2005.10, We report the effects of oxygen post-annealing on critical current properties and normal state resistivities in ErBa2Cu3Oy /SrTiO3(Er123/STO) thin films fabricated in the substrate temperature range from 720 degrees C to 780 degrees C by pulsed laser deposition (PLD). Interestingly, for films fabricated below 760 degrees C, the critical current density (J(c)) increased by oxygen post-annealing process from 0.3-0.6 x 10(6) A cm(-2) to the order of 10(6) A cm(-2) for the as-deposited films despite critical temperatures (T,) of -90 K for both annealed and as-deposited films. In the 780 degrees C-deposited film, Jc was not obviously enhanced. X-ray diffraction and measurement of normal state resistivities revealed that the PLD-Erl 23/STO films showed high-quality crystallographic and electrical properties in films deposited below 760 degrees C. In high temperature resistivity measurements, the resistivity reduced with annealing time and showed a systematic change with changing oxygen partial pressure. These results strongly suggest that oxygen post-annealing is indispensable for improving J(c) in 123 films fabricated through a non-equilibrium process such as the PLD method even though the as-deposited films show a T-c value of similar to 90 K. (c) 2005 Elsevier B.V. All rights reserved..
67. A Ichinose, K Matsumoto, M Mukaida, Y Yoshida, S Horii, S Akita, Microstructures of high-T-c superconducting films having artificial pinning centers, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 10.1109/TASC.2005.849412, 15, 2, 3718-3721, 2005.06, REBa2Cu3Oy (REBCO) is expected to be used in numerous applications, such as power transmission cables, high-field magnets and generators, due to the possibility of a high critical current density at 77 K under a high magnetic field. Biaxially textured REBCO superconducting tapes are developed to obtain high-J(c). However, the J(c) - B characteristics of REBa2Cu3Oy films have a magnetic field angle dependency. When the magnetic field is applied parallel to the film surface, the reduction in J(c) is not larger under a high magnetic field of 10 T. When the magnetic field is applied perpendicular to the film surface, the reduction in J(c) is significantly large under a magnetic field of more than around 5 T at 77 K. From the viewpoint of realizing wide applications of high-T-c superconductors, it is important to improve the J(c) - B characteristics of REBCO films under magnetic fields higher than 5 T applied perpendicular to the film surface. Our group focuses on artificial pinning centers (APCs) introduced into REBCO films. The J(c) - B characteristics of certain films are improved by the introduction of APCs. The microstructures of these films are investigated using transmission electron microscopy (TEM). We report on the microstructures of REBCO films with APCs..
68. M Ito, M Mukaida, T Ohazama, R Kita, A Ichinose, S Horii, A Saito, K Matsumoto, Y Yoshida, K Koike, F Hirose, S Ohshima, Microstructure of ErBa2Cu3O7-delta films with BaZrO3 dispersion pinning centers for high J(C) applications, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2005.02.109, 426, 1415-1418, 2005.10, ErBa2Cu3O7-delta thin films with BaZrO3 dispersion pinning centers for high J(C) applications were grown using ErBa2Cu3O7-delta targets with various BaZrO3 contents. The J(C) improvement at high applied magnetic fields was observed for the ErBa2Cu3O7-delta films with BaZrO3 dispersion pinning centers. From the cross-sectional transmission electron microscope images of the ErBa2Cu3O7-delta films With BaZrO3 dispersion pinning centers, we believe that the BaZrO3 nano-particles in ErBa2Cu3O7-delta films play a role of pinning centers. Increase of the amount of BaZrO3 nano-particles in ErBa2Cu3O7-delta films induced drastic reduction of the surface resistance (R-S). This result suggests that the ErBa2Cu3O7-delta films with BaZrO3 nano-particles can be applied to high power microwave emitting devices. (c) 2005 Published by Elsevier B.V..
69. T Ohazama, M Mukaida, S Horii, A Saito, R Kita, A Ichinose, Y Yoshida, K Matsumoto, S Ohshima, Low surface resistance Zn-doped ErBa2Cu3O7-delta thin films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2005.02.125, 426, 1611-1615, 2005.10, The Zn-doped ErBa2Cu3O7-delta thin films were prepared by a pulse laser deposition (PLD) on a SrTiO3, which is a lattice, matched substrate. The various contents of the Zn-doped ErBa(2)Ci(3)O(7-delta),5 ceramics were used as the targets. All the films were grown at 750 degrees C under an oxygen pressure of 400 mTorr. From the X-ray diffraction (XRD) patterns, only the 001 reflections were observed. Surface resistance (R-S) measurement revealed that the ErBa2(CU0.9Zn0.1)O7-delta films showed a superconducting transition temperature (T-C) below 70 K. The R-S value of the ErBa2(Cu0.997Zn0.1)(3)O7-delta films and that of the ErBa2(Cu0.995Zn0.005)(3)O7-delta films was lower than that of the ErBa2Cu3O7-delta films for wide temperature region of 10-90 K. From the observation of the atomic force microscopy (AFM), a lot of pores were observed in the surface of the Zn-doped ErBa2Cu3O7-delta,5 films, which showed a low R-S. (c) 2005 Elsevier B.V. All rights reserved..
70. K Matsumoto, T Horide, P Mele, A Ichinose, S Horii, Y Yoshida, M Mukaida, K Osamura, J(c) enhancement in YBa2Cu3Ox thin films by introduction of one-dimensional artificial pinning centers, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 10.1109/TASC.2005.849428, 15, 2, 3774-3777, 2005.06, A novel technology to introduce artificial pinning centers (APCs) into YBa2Cu3O7-delta (YBCO) thin films prepared by pulsed laser deposition (PLD) was investigated for a drastic improvement of J(c) in the films. Linear-like defects (one-dimensional APCs) were introduced perpendicular to the surface of the c-axis oriented films during the deposition process by using distributed Y2O3 nano-islands on substrates. The density of nano-islands was varied within 0.8 - 1.2 x 10(10)/cm(2) by PLD. A normalized resistivity as a function of temperature in magnetic fields shows a sharper resistivity drop for the film with APC, compared to pure YBCO film. J(c) of the film with APC was also increased to 0.12 MA/cm(2) (77 K, B//c, 5 T), which was about two times higher than that of the pure YBCO film. The film had a very large Jc peak when the field was applied close to the c-axis. The peak J(c) increased with the number density of Y2O3 nano-islands. This indicates that strong APCs parallel to the c-axis were incorporated into the YBCO film..
71. Y Yoshida, K Matsumoto, M Miura, Y Ichino, Y Takai, A Ichinose, M Mukaida, S Horii, J(c) characteristics in high magnetic field and microstructure of RE1+xBa2-xCu3O6+y films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2005.01.059, 426, 1043-1050, 2005.10, We have investigated the superconducting properties and the microstructure of c-axis oriented Sm1+xBa2-xCu3O6+y (SmBCO) thin films deposited on MgO substrates by pulsed laser deposition (PLD). In particularly, the use of thin c-axis oriented seed layer grown at high temperature enabled us to obtain fully c-axis oriented SmBCO films at relatively low temperature (similar to 740 degrees C). The values of T-c for the present films are within the range of 91.5-92.5 K. From their J(c)-B characteristics, it has been observed that the superconducting properties of SmBCO (x = 0.04, 0.08) films are superior to those of the YBa2Cu3O7-y thin films for B parallel to c, 5 T at 77 K. The J(c) values of the SmBCO films measuring 2.8 x 10(5) A/ m(2) for 5 T of B parallel to c at 77 K are comparable to that of NbTi for 5 T at 4.2 K. Furthermore, the superconducting properties in SmBCO change with the substitution of Sm-Ba. The Electron microscopic studies with EDX and S-TEM analysis have revealed that the Sm/Ba ratio fluctuates within the range of x = 0-0.14 with a wavelength of similar to 100 nm. High-J(c) values in high magnetic fields at 77 K demonstrate the potential of REBCO films for high-field applications of oxide superconductor. (c) 2005 Elsevier B.V. All rights reserved..
72. M Miura, M Itoh, Y Yoshida, Y Ichino, Y Takai, K Matsumoto, A Ichinose, S Horii, M Mukaida, In-plane alignment and superconducting properties in high-J(c) Sm1+xBa2-xCu3O6+delta thin films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2005.02.088, 426, 985-989, 2005.10, We have fabricated films of high-J(c) Sm1+xBa2-xCu3O6+delta (SmBCO) using a low temperature growth (LTG) technique. The self-field J(c) of LTG-SmBCO film increased with decreasing the substrate temperature at the upper layer fabrication (T-s,T-upper). From X-ray phi-scan measurement, we confirmed three kinds of in-plane rotated grains in the LTG-SmBCO films. The main peaks correspond to the grain with a [100](MgO)broken vertical bar broken vertical bar[100](SmBCO). Other small peaks observed from the grain with 45 degrees rotation and 45 +/- 8 degrees rotation decreased with decreasing T-s,T-upper. We considered that high-J(c) SmBCO films resulted from the improvement of the in-plane alignment. (c) 2005 Elsevier B.V. All rights reserved..
73. Y Yoshida, Y Ichino, M Miura, Y Takai, K Matsumoto, A Ichinose, S Horii, M Mukaida, High critical current density in high field in Sm1+xBa2-xCu3O6+y thin films, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 10.1109/TASC.2005.847798, 15, 2, 2727-2730, 2005.06, Critical current density (J(c)), irreversibility field (B-irr) and microstructure in epitaxial SmBa2Cu3O7-x. (SmBCO) films are reported. We have developed a novel approach to deposit high performance Sm1+xBa2-xCu3O6+y (Sm-123) at relatively low substrate temperature on MgO. The use of thin SmBCO seed layer grown at a high substrate temperature enabled us to obtain fully c-axis oriented SmBCO films with high critical current density (J(c)) of 2.8 X 105 A/cm(2) under 5 T for B//c at 77 K. This value is as high as in the optimized NbTi superconducting wires achieved for 5 T at 4.2 K. Compared with YBa2Cu3O7-y films, Sm-123 films showed higher J(c) in high fields at 77 K. Transmission electron microscopy TEM analyses clarified the Sm/Ba composition ratio fluctuations in the Sm-123 matrix composition in the range of x = 0 similar to 0.14 with a wavelength of 50 similar to 100 nm..
74. M Miura, M Mukaida, A Saito, A Ichinose, S Horii, R Kita, Y Yoshida, K Matsumoto, K Koike, S Ohshima, Growth of EuBa2Cu3O7-delta films under an ozone atmosphere, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2005.02.140, 426, 1429-1433, 2005.10, We have investigated the dependence of the crystallinity and the superconducting characteristics in the EuBa2Cu3O7-delta (EuBCO) thin films on oxygen content. The EuBCO films were grown using a pulsed laser deposition (PLD) under an oxygen and an ozone atmosphere on (100) SrTiO3 substrates. The c-axis length of as-grown EuBCO films under the oxygen atmosphere was longer than that of the bulk. The c-axis length of in situ annealed EuBCO films was shortened as compared with the as-grown EuBCO films. Additionally, the surface resistance (R,) of the in situ 3 and 6 h annealed EuBCO films was lower than that of as-grown EuBCO films. However, the surface resistance of in situ annealed more than 24 h EuBCO films was not lower than that of in situ 6 h EuBCO films. The c-axis length of the as-grown EuBCO films grown under an ozone atmosphere showed 1.170 nm. It must be noted that the lowest surface resistance of EuBCO films was obtained by EuBCO films grown under the ozone atmosphere without any in situ annealing. We found that the growth of EuBCO films under the ozone atmosphere was good to dope oxygen in the films. (c) 2005 Published by Elsevier B.V..
75. Y Shingai, M Mukaida, K Matsumoto, Y Yoshida, A Ichinose, S Horii, K Koike, F Hirose, A Saito, S Ohshima, Growth and characterization of a-axis oriented ErBa2Cu3O7-delta films using double buffer layers, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2005.03.056, 426, 1424-1428, 2005.10, We have grown a-axis oriented ErBa2Cu3O7-delta (ErBCO) films. Crystallinity of ErBCO films grown on Gd2CuO4 (GCO) buffer layers are investigated at various growth temperatures, in order to find a condition to fabricate a-axis oriented ErBCO films. a-Axis oriented ErBCO films are also grown at a high growth substrate temperature by using YBa2Cu3O7-delta (YBCO)/GCO double buffer layers. We have successfully fabricated a-axis oriented ErBCO films with the GCO buffer layer by optimizing the substrate temperature during growth. Furthermore, we optimized growth temperatures for a-axis oriented ErBCO films are increased by using the YBCO/GCO buffer layer. (c) 2005 Elsevier B.V. All rights reserved..
76. Y Shingai, M Mukaida, A Ichinose, S Horii, Y Yoshida, K Matsumoto, F Hirose, K Koike, A Saito, S Ohshima, Fabrication of a/c axes oriented grain boundaries in YBCO films by selective growth, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 10.1109/TASC.2005.848653, 15, 2, 2935-2938, 2005.06, The a/c axes grain boundaries of YBCO films are very interesting from the viewpoints of Josephson junction technology and the magnetic flux pinning. In this paper, we intend to flow superconducting current along the grain boundary and to prevent the magnetic flux motion from passing across the grain boundary. The a/c axes grain boundaries were fabricated on SrLaGaO4 (100) substrates by pulsed laser deposition on Gd2CuO4 (GCO) buffer layers. The preferred orientation and in-plane orientation of the films were characterized by X-ray theta/2 theta diffraction and phi-scan spectroscopy. 4-micrometer pitch GCO patterns were fabricated by a lithography technology. Subsequently, the YBCO films were deposited on the pattern. A TEM image showed that a-axis grains grew over c-axis grains..
77. K Matsumoto, T Horide, P Mele, Y Yoshida, M Mukaida, A Ichinose, S Horii, Effects of artificial pinning centers on vortex pinning in high-temperature superconducting films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2005.02.094, 426, 1091-1095, 2005.10, One-dimensional artificial pinning centers (APCs) were introduced perpendicular to the surface of the c-axis oriented YBa2Cu3O7-delta (YBCO) films by Using Y2O3 nano-islands which were distributed on the substrates. In-field J(c) of the films was remarkably enhanced by this method and reached to 0.12 MA/cm(2) (77 K, B parallel to c, 5 T), which was 2-2.5 times higher than that of a pure YBCO film. The present films had a large J(c) peak when the field was applied close to the c-axis. The results indicate that the strong APCs were introduced into the YBCO films. The vortex pinning by the present APCs is discussed based on the accommodation angle of the vortices. (c) 2005 Elsevier B.V. All rights reserved..
78. R Honda, Y Ichino, Y Yoshida, Y Takai, K Matsumoto, A Ichinose, R Kita, M Mukaida, S Horii, Effect of substituted rare earth element in (Yb1-xNd,)Ba2CU30Y thin film on growth orientation and superconducting properties, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2005.06.004, 426, 1005-1009, 2005.10, We studied the orientation and superconducting properties in (Yb1-xNdx)Ba-2-Cu3Oy (Yb/Nd123) thin films as a function of Yb/Nd composition ratio x. As a results, we needed so high oxygen pressure as to increase x for obtaining the c-axis oriented films. J(c)-B curves in the Yb/Nd123 thin films were superior to that in YBa2Cu3Oy thin film. Since a RE fluctuation in a composition in the Yb/Nd123 thin films was observed with TEM-EDX, we speculated the pinning centers in the Yb/Nd123 thin films were strongly affected by the RE fluctuation. (c) 2005 Elsevier B.V. All rights reserved..
79. M Miura, M Itoh, Y Ichino, Y Yoshida, Y Takai, K Matsumoto, A Ichinose, S Horii, M Mukaida, Effect of Sm/Ba substitution on the J(c) in magnetic field of SmBCO thin films by low temperature growth technique, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 10.1109/TASC.2005.848962, 15, 2, 3078-3081, 2005.06, We have reported superconducting properties of Sm1+xBa2-xCu3Oy (SmBCO; x = 0.08) thin films prepared by the low temperature growth technique (LTG). LTG process is consisted of two steps as follows; a seed layer is deposited at 830 degrees C on MgO(100), and then upper layer is deposited at 740-780 degrees C on the seed layer. In order to investigate the effect of the fluctuations Sm/Ba composition ratio in the SmBCO matrix, we deposited upper layer with the Sm/Ba composition of x = 0 - 0.12. The SmBCO films with x = 0.04 and 0.08 show critical current density (J(c)) at 77 K of up to 5 x 10(6) A/cm(2) under 0 T and 1 x 10(5) A/cm(2) under 5 T for B//c at 77 K, respectively. The J(c) of x = 0.12 film dropped more sharply compared with the cases of x = 0.04 and 0.08 films. From the microstructure analysis, it was found that the main phase of x = 0.12 film was Sm-rich (Sm1.1Ba1.9Cu3Oy) phase, while that of x = 0.04 and 0.08 films was stoichiometry. We speculated that the low-J(c) of x = 0.12 film in the magnetic fields was ascribed to the low physical meters of T-c and irreversibility field of the Sm-rich SmBCO main phase..
80. R Kita, K Nezu, K Yokoyama, K Matsumoto, Y Yoshida, M Mukaida, S Horii, A Ichinose, Effect of AZrO(3) and AWO(4) (A = Ba, Sr and Ca) addition on the superconducting properties of ErBa2Cu3Oy, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2005.02.064, 426, 550-555, 2005.10, We have investigated the stability of AZrO(3) and AWO(4) (A = Ba, Sr and Ca) in the ErBa2CU3Oy (Er123) matrix, and the effect of their addition on the superconducting properties of Er 123. No degradation of T-c(zero) was observed for the Er123 samples with BaZrO3 and SrZO(3) addition up to 0.5 wt.%, and with BaWO4 and SrWO4 addition up to 1.0 wt.%. T-c(onset) was not affected by the AZrO(3) and AWO(4) addition for all the samples. The BaZrO3-added samples showed uniform distribution of BaZrO3 fine particles. It was found that BaZrO3 and BaWO4 were most stable in the Er123 matrix among AZrO(3) and AWO(4) materials. (c) 2005 Published by Elsevier B.V..
81. M Mukaida, M Miura, A Ichinose, S Horii, K Matsumoto, Y Yoshida, K Koike, Y Takahashi, A Saito, S Ohshima, Crystal distortion associated with ortho-tetra transition of REBa2Cu3Ox, films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2005.02.149, 426, 1010-1014, 2005.10, Microstructure deformation has been investigated for EuBa2Cu3Ox films associated with orthorhombic-tetragonal transition during cooling in an oxygen atmosphere. EuBa2CU3Ox films have been grown by a pulsed laser deposition technique under 1000 mTorr oxygen pressure and 800 degrees C substrate temperature. After the growth, the films are cooled to 400 degrees C and annealed in one atom oxygen pressure for 0-110 h. The preferred orientation of the films is characterized by X-ray diffraction and phi-scan X-ray diffraction. Microstructures and lattice images of the EuBa2Cu3Ox films are observed by a transmission electron microscope. All of the obtained EuBa2Cu3Ox films are c-axis oriented. The phi-scan X-ray diffraction revealed that films without any 500 degrees C annealing have a tetragonal structure. However, more than 3 h annealed films are partly orthorhombic from the peak separation in the phi-scan. The angle between the two peaks is about 0.8 degrees. We estimate the a-axis length/b-axis length ratio (orthorhombicity) from the angle between the separated peaks to be 0.866 degrees. It agrees with the a-axis length/b-axis length ratio of well oxidized EuBa2Cu3Ox bulk materials. (c) 2005 Elsevier B.V. All rights reserved..
82. P Mele, K Matsumoto, T Horide, O Miura, A Ichinose, M Mukaida, Y Yoshida, S Horii, Control Of Y2O3 nanoislands deposition parameters in order to induce defects formation and its influence on the critical current density of YBCO films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2005.03.043, 426, 1108-1112, 2005.10, We successfully introduced high-density linear defects as artificial pinning centers (APCs) of the quantized vortices into YBCO films, during the film deposition procedure. APCs were introduced perpendicular to the film surface by using the distributed nanosized Y2O3 islands prepared on SrTiO3(100) substrates. It is possible to induce strong changes on the shape and density of the Y2O3 islands by varying the deposition conditions. The highest Y2O3 islands density, 226/mu m(2), was obtained with fifteen laser pulses at 800 degrees C of substrate temperature. Even if only 10% of the induced defects act as effective pinning centers, J(c) of YBCO film grown on the Y2O3 nanoislands/SrTiO3 substrate increased to 1.8 x 10(7) A/cm(2) (20 K, B parallel to c, 0 T), which is 1.5 times higher than that of the pure YBCO film. (c) 2005 Elsevier B.V. All rights reserved..
83. T Horide, K Matsumoto, A Ichinose, Y Yoshida, S Horii, M Mukaida, K Osamura, Angular dependence of critical current density in Y-Ba-Cu-O thin films, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 10.1109/TASC.2005.849417, 15, 2, 3734-3737, 2005.06, c-axis oriented YBa2Cu3O7-delta (YBCO) thin films for coated conductor applications have anisotropic behaviors of critical current density (J(c)) in magnetic fields. The anisotropic vortex pinning in YBCO films fabricated on SrTiO3(100) single crystal substrates by pulsed laser deposition was investigated based on the field angular dependencies of J(c), which were measured using the constant Lorentz force configuration (CLFC) and a variable Lorentz force configuration (VLFC). J(c)(theta) as a function of angle theta between the ab-plane direction and the magnetic field direction had a sharp peak at theta = 0 degrees, which was attributed to the intrinsic pinning. Besides, J(c)(theta) did not depend on the intensity of the Lorentz force when the magnetic field was applied near theta = 90 degrees. This indicates that J(c)(theta) in this region is determined by the depinning of the vortex segment trapped by the pinning centers parallel to c-axis of the film. A transition from the intrinsic pinning to the extrinsic pinning is also discussed..
84. K. Yamada, A. Ichinose, Y. Shingai, K. Matsumoto, Y. Yoshida, S. Horii, R. Kita, S. Toh, K. Kaneko, N. Mori, M. Mukaida, TEM observation of ErBa2Cu3O7-delta films with BaZrO3 artificial pinning centers, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2006.06.012, 445, 660-664, 2006.10, Microstructure of ErBa2Cu3O7-delta films with BaZrO3 as artificial pinning centers has been studied toward power application of a high temperature superconductor. ErBa2Cu3O7-delta films containing 1.5 mass% BaZrO3 were grown by a pulsed laser deposition method. Microstructure of the ErBa2Cu3O7-delta 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-delta film were observed. Width of the nano-rods was about 10 nm. We found twins with the averaged width of about 70 nm. The moire fringes were also observed. In the EDS mapping analysis, zirconium was not detected clearly from the present TEM specimen. Space of the moire fringes is about 1.9 nm. The lattice constant of a material in the ErBa2Cu3O7-delta film measured from the space of the moire 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-delta film as the nano-rods. (c) 2006 Elsevier B.V. All rights reserved..
85. M. Mukaida, A. Saito, R. Kita, K. Matsumoto, A. Ichinose, Y. Yoshida, S. Horii, K. Yamada, N. Mori, Surface resistance of RE123 films with artificial pinning centers, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2006.05.074, 445, 828-832, 2006.10, Effects of artificial pinning centers (APCs) into ErBa2Cu3O7-delta films are discussed. The APCs used in this paper is BaZrO3 and Zn which are mixed into ErBa2Cu3O7-delta ceramic targets. The targets with various contents of APCs are ablated and films are grown on substrates with the APCs. X-ray diffraction patterns show there are no other phases than ErBa2Cu3O7-delta and APCs. Transmission electron microscopy (TEM) shows the BaZrO3 APSs grow along the c-axis of the films. The introduction of APCs decreases surface resistance (R-S) of ErBa2Cu3O7-delta films and increases critical current density (J(C)) of the films. R-S measurements revealed that the ErBa2Cu3O7-delta films with APCs showed a lower R-S than that of the ErBa2Cu3O7-delta films without APCs. (c) 2006 Published by Elsevier B.V..
86. K. Yokoyama, R. Kita, K. Matsumoto, Y. Yoshida, M. Mukaida, S. Horii, A. Ichinose, Superconducting properties and orientation behavior of REBa 2Cu3Oy (RE = Yb, Er, Sm, Nd and La) films by metal-organic deposition, Modern Physics Letters B, 10.1142/S0217984906011207, 20, 12, 705-713, 2006.05, We have investigated superconducting properties and orientation behavior of RE123 (RE = Yb, Er, Sm, Nd and La) films on MgO and SrTiO3 substrates by metal-organic deposition technique using metal naphthenates. On MgO substrates, only Yb123 films showed superconducting transition with T c(zero) of 77.0 K and c-axis orientation with in-plane alignment. On SrTiO3 substrates, Yb123, Er123, Sm123, Nd123 and La123 films showed c-axis orientation with in-plane alignment, and Tc(zero) of 89.5 K, 89.7 K, 80.5 K, 85.0 K and 47.6 K, respectively. Sm123 and La123 films showed square and plate-like grains on MgO substrates, and relatively flat surface covered with well-grown grains on SrTiO3 substrates. © World Scientific Publishing Company..
87. K. Yokoyama, R. Kita, A. Ichinose, O. Miura, K. Matsumoto, Y. Yoshida, M. Mukaida, S. Horii, Superconducting properties of REBa2Cu3Oy (RE = Y and Gd) films prepared by BaF2 process without water vapor, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2006.04.052, 445, 587-589, 2006.10, We have successfully fabricated YBa2Cu3Oy (Y123) and GdBa2Cu3Oy (Gd123) films on SrTiO3 substrates by the ex situ heat treatment of co-evaporated Y-BaF2-Cu and Gd-BaF2-Cu precursor films prepared by electron beam deposition technique without water vapor. T-c and J(c) of the Y123 film were 91.6 K and 0.95 MA cm(-2) at 77 K at self-field, respectively. The Gd123 film showed T-c of 93.4 K and J(c) of 1.5 MA cm(-2) at 77 K at self-field. It was found that the surface morphology of the Y123 and the Gd123 films depended on the partial oxygen pressure during the heat treatment. (c) 2006 Elsevier B.V. All rights reserved..
88. Y Ichino, H Matsuo, Y Yoshida, Y Takai, K Matsumoto, M Mukaida, A Ichinose, S Horii, Possibility of high deposition rate in SmBa2Cu3Oy films prepared using the vapor-liquid-solid growth mode, JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 10.1143/JJAP.45.758, 45, 2A, 758-760, 2006.02, The vapor-liquid-solid (VLS) growth mode is expected to achieve high-quality REBa2Cu3Oy thin films at a high growth rate since it is almost identical to the liquid phase epitaxy (LPE) growth mode. We studied the effect of the deposition rate on superconductivity in SmBa2Cu3Oy (Sm123) thin films prepared using the VLS growth mode. The VLS-Sm123 films as well as that deposited by pulsed laser deposition (PLD) under optimal conditions had completely c-axis orientation and maintained high crystallinity. Critical temperatures were around 90K and independent of the deposition rate. However, critical current densities increased with the deposition rate and reached over 1 MA/cm(2) at 77 K. In this study, a maximum deposition rate of 320 nm/min was achieved; this was thirty times as high as that obtained by PLD. We propose that a deposition rate as high as that obtained by LPE can be achieved by the VLS growth mode..
89. Y. Shingai, T. Abe, M. Mukaida, R. Kita, Y. Yoshida, A. Ichinose, S. Horii, K. Matsumoto, A. Saito, K. Yamada, N. Mori, Improvement of superconducting properties by BaTiO3 doping into ErBa2Cu3O7-delta films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2006.05.037, 445, 841-844, 2006.10, We have improved surface resistance (R-S) properties of ErBa2Cu3O7-delta (ErBCO) films by using BaTiO3 (BTO) doping (BTO + ErBCO). The as-grown BTO + ErBCO films did not have enough carriers. We solve this problem by using O-3 + O-2 as background gas during the growth of BTO + ErBCO films. Then, O-3 + O-2 gas is useful to grow BTO + ErBCO films with superior superconducting properties. The R-S of a 2 wt.%BTO + ErBCO film is the lowest in BTO + ErBCO films grown in this study. This value is equal to that of a 1.5 wt.%BZO + ErBCO film. The microstructures of the 2 wt.%BTO + ErBCO film are observed by transmission electron microscopy (TEM). In the image, the BTO + ErBCO films did not have the same nanorods as observed in the BZO + ErBCO films against our expectation. However, precipitates that the BZO + ErBCO films do not have, are observed. (c) 2006 Elsevier B.V. All rights reserved..
90. T. Minei, T. Tanaka, M. Ogata, N. Mori, K. Yamada, M. Mukaida, Growth process and microstructure of Y123 film fabricated by advanced TFA-MOD process, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2006.04.050, 445-448, 1-2, 570-573, 2006.10, The advanced metal organic deposition (MOD) process using F-free salt of Cu and trifluroacetates (TFA) salts (Superconductivity Research Laboratory (SRL)-Method) was applied to form well oriented Y123 film on LaAlO3 substrate. In order to clarify the growth mechanism of the Y123 film by the advanced TFA-MOD process, two methods were introduced. One was the quenching method to get samples under several different conditions during the process, and the microstructures were observed by transmission electron microscopy (TEM). The other was in situ observation method to know surface changes of the film by the generation of liquid and/or gas. From the θ-2θ X-ray diffraction (XRD) analysis of YBa2Cu3O7-δ (YBCO) films fabricated by suitable conditions, (0 0 n) diffraction peaks were obtained indicating they had strongly c-axis oriented structure. The thin YBCO films had critical current density (JC) of 3.8-4.9 MA/cm2 (77 K,0 T) measured by the four-probe-method. A growth model with some process-controlling parameters was proposed based on the above observed results. © 2006 Elsevier B.V. All rights reserved..
91. M. Haruta, T. Fujiyoshi, T. Sueyoshi, K. Dezaki, D. Ichigosaki, K. Miyahara, R. Miyagawa, M. Mukaida, K. Matsumoto, Y. Yoshida, A. Ichinose, S. Horii, Flux pinning properties of ErBa2Cu3Oy thin films with BaZrO3 nanorods, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 10.1088/0953-2048/19/8/019, 19, 8, 803-807, 2006.08, ErBa2Cu3Oy (ErBCO) thin films with BaZrO3 (BZO) nanorods were prepared by a PLD method for an enhancement of the critical current density J(c). The values of J(c) for the ErBCO thin film containing 1.5 wt% BZO (Er15) in magnetic fields are higher than those for the ErBCO thin film containing 0.5 wt% BZO (Er05). The peaks of J(c) have been observed in the angular dependence of Jc in both the films when the magnetic field is applied parallel to the c-axis. It has been found that the peak is attributed to the flux pinning by BZO nanorods oriented parallel to the c-axis. The vortex glass - liquid transition temperature T-g and the pinning parameter m were derived by fitting observed electric transport properties to the theoretical expression based on the percolation transition model. The value of Tg of Er15 is higher than that of Er05. This result indicates that the vortex glass phase extends to a higher temperature region on increasing the fraction of BZO. The peak of m has been found in the magnetic field dependence. This fact is probably due to matching the density of BZO nanorods with that of fluxoids, which was confirmed by TEM observations..
92. T. Horide, T. Horide, K. Matsumoto, K. Matsumoto, H. Adachi, D. Takahara, D. Takahara, K. Osamura, A. Ichinose, A. Ichinose, M. Mukaida, M. Mukaida, Y. Yoshida, Y. Yoshida, S. Horii, S. Horii, Evaluation of metallic nanoparticles in REBa2Cu3O7-δ (RE = Y, Gd) thin films by small angle X-ray scattering, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2006.04.061, 445, 652-655, 2006.10, Nanoparticles should be strong artificial pinning centers in high-temperature superconducting films. We successfully used pulse laser deposition to introduce gold nanoparticles in REBa2Cu3O7-δ (RE = Y, Gd) films. We used small angle X-ray scattering (SAXS) to obtain macroscopic information for the nanoparticles. SAXS showed that the average spacing and radius of the nanoparticles were 110-160 nm and 14-18 nm, respectively, which were consistent with the results from transmission electron microscopy. SAXS also suggested that the interface between the REBa2Cu3O7-δ matrix and the nanoparticles is sharp. This indicated that gold nanoparticles could work as strong artificial pinning centers. © 2006 Elsevier B.V. All rights reserved..
93. M Miura, Y Yoshida, Y Ichino, Y Takai, K Matsumoto, A Ichinose, S Horii, M Mukaida, Enhancement of flux-pinning in epitaxial Sm1+xBa2-xCU3Oy films by introduction of low-T-c nanoparticles, JAPANESE JOURNAL OF APPLIED PHYSICS PART 2-LETTERS & EXPRESS LETTERS, 10.1143/JJAP.45.L11, 45, 1-3, L11-L13, 2006.01, Sm1+xBa2-xCu3Oy (SmBCO) films prepared by the low-temperature growth (LTG) technique showed a critical current density (J(c)) as high as 0.28 MA/cm(2) (77 K B // c, B = 5 T). However, J(c) was lower than that of NbTi wire (4.2 K) above 5 T. In this study, we introduced nanoparticle superconductors with a low critical temperature (low-T-c) into LTG-SmBCO "LTG-SmBCO + nanoparticle" films to improve J(c) under the high magnetic field, and obtained an extremely high J(c), 0.1 MA/cm(2) (77 K B // c, B = 8 T). Energy-dispersive X-ray spectroscopy (EDX) showed that the "LTG-SmBCO + nanoparticle" films had a nanosize low-T-c phase and a low-T-c network dispersed in the high-T-c matrix. We concluded that the "LTG-SmBCO + nanoparticle" films could have enhanced J(c) by the introduction of pinning centers and the improvement of irreversibility field (B-irr)..
94. 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-delta superconducting thin films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2006.06.016, 445, 845-848, 2006.10, Surface resistances (R-S) have been measured for EuBa2Cu3O7-delta (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 (100) 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. (c) 2006 Published by Elsevier B.V..
95. R. Kita, T. Naito, A. Shiraishi, K. Oidaira, T. Nakamura, O. Miura, K. Matsumoto, Y. Yoshida, M. Mukaida, S. Horii, A. Ichinose, Effect of Ta2O5 addition on the superconducting properties of REBa2Cu3Oy, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2006.04.024, 445, 391-394, 2006.10, We have investigated the effect of Ta2O5 addition on the superconducting properties of REBa2Cu3Oy (RE = Er, Sm and Eu: REBCO) prepared by a powder-sintering method. T-c(zero) values showed no degradation up to 1.0 wt.% Ta2O5 addition for ErBCO samples. EuBCO and SmBCO samples showed the increase in Tc(zero) from 89 K to 94 K by the addition of I wt.% Ta2O5, and 80 K to 94 K by the addition of 2 wt.% Ta2O5, respectively. J(c) values at B=0.5 T increased by two times the pure samples for ErBCO with 1.0 wt.% addition, four times for EuBCO with 1.5 wt.% addition, and 33 times for SmBCO with 1.0 wt.% addition. The formation of REBa2TaO6 was observed for the Ta2O5-added REBCO samples. (c) 2006 Elsevier B.V. All rights reserved..
96. Masashi Miura, Yutaka Yoshida, Yusuke Ichino, Toshinori Ozaki, Yoshiaki Tarai, Kaname Matsumoto, Ataru Ichinose, Shigeru Horii, Masashi Mukaida, Dislocation density and critical current density of Sm1+xBa 2-xCu3Oy films prepared by various fabrication processes, Japanese Journal of Applied Physics, Part 2: Letters, 10.1143/JJAP.45.L701, 45, 24-28, L701-L704, 2006.07, Dislocations are effective flux-pinning centers in REBa2Cu 3Oy films at a magnetic field. To investigate the relationship between critical current density (Jc) and dislocation density, we discussed the dislocations in conventional pulsed-laser-deposition (PLD)-SmBCO films, vapor-liquid-solid (VLS)-SmBCO films, and low-temperature growth (LTG)-SmBCO films. The LTG-SmBCO and VLS-SmBCO films showed high-J c at low magnetic fields. From the observation of etch pits, we found that the LTG-SmBCO and VLS-SmBCO films had high-dislocation densities. We speculate that Jc at low-magnetic fields is affected by dislocation density. LTG is effective for increasing dislocation density without deteriorating crystallinity or superconducting properties. © 2006 The Japan Society of Applied Physics..
97. S. Horii, Y. Ichino, Y. Yoshida, K. Matsumoto, M. Mukaida, A. Ichinose, J. Shimoyama, K. Kishio, Dilute Co-doping effects on critical current properties in PLD-ErBa2Cu3Oy films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2006.05.036, 445, 837-840, 2006.10, We report the effects of dilute Co-doping on superconducting and critical current properties in ErBa2Cu3Oy/SrTiO3 (Er123/STO) thin films fabricated by pulsed laser deposition (PLD). Critical temperatures (T-c) were systematically increased with substrate temperature (T-s), and therefore the substitution levels of Co into the CuO2 planes can be controlled by T-s On the other hand, the critical current density (J(c)) increased with the decrease in T-s at low temperatures below 50 K. The angular dependence of J(c) for the films with relatively heavier Co-doping levels showed the c-axis peaks, which is quite contrast to that for the pure Er123 film. This behavior was observed not only at low temperatures but also at high temperatures. These results indicate that the Co-doping induced generation of the c-axis correlated vortex pinning centers in the Er123 matrix and this new type of pinning center is probably due to the existence of inhomogeneous distribution of the Co-doping levels in the films. (c) 2006 Elsevier B.V. All rights reserved..
98. P. Mele, K. Matsumoto, T. Horide, O. Miura, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, Critical current enhancement in PLD YBa2Cu3O7-x films using artificial pinning centers, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2006.04.064, 445, 648-651, 2006.10, We introduced high-density columnar defects as artificial pinning centers (APCs) for quantized vortices into YBa2Cu3O7-x (YBCO) films during the film deposition procedure. APCs were introduced perpendicular to the film surface using nano-sized Y2O3 islands prepared on SrTiO3 (100) substrates. Varying the deposition parameters and the substrate annealing conditions allowed strong changes in the shape and density of the Y2O3 islands to be induced. Compared to a pure YBCO film, the best performance among the APCs samples was obtained on the Y2O3-deposited substrate with 5 laser pulses, corresponding to a nominal thickness of 0.2 nm. Even when the APC films were prepared using the same deposition conditions, the columnar defects enhanced J(c) at 77 K from 1.8 to 2.7 MA/cm(2) (self field) and from 0.06 to 0.10 MA/cm(2) (H = 5 T, H parallel to c-axis). (c) 2006 Elsevier B.V. All rights reserved..
99. Y. Yoshida, K. Matsumoto, M. Miura, Y. Ichino, Y. Takai, A. Ichinose, M. Mukaida, S. Horii, Controlled nanoparticulate flux pinning structures in RE1+xBa2-xCu3Oy films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2006.04.059, 445, 637-642, 2006.10, Practical utilization of a coated conductor as a superconducting magnet operating at 77 K requires not only an improvement in the J(c) at self field but also suppression of any decline in the Jc value in the magnetic field. In this study, nanoparticles and crystalline defects were created as the flux pinning in a high-J(c) Sm1+xBa2-xCu3Oy film during a film deposition process. We obtained extremely high-Jc values, J(c) = 0.37 MA/cm(2) (77 K, B parallel to c, B = 5 T) and J(c) = 0.1 MA/cm(2) (77 K, B parallel to c, B = 8 T). Cross-sectional low magnification and high-resolution TEM micrographs confirm the presence of Sm-enriched nanoparticles (x value > 0.2) embedded in the SmBCO lattice; typical particle sizes were 15 nm and particle density about 10(10)-10(11) particles cm(-2). We discussed about the elemental mapping of the high-J(c) SmBCO films measured by TEM-EDX. (c) 2006 Elsevier B.V. All rights reserved..
100. Yusuke Ichino, Masashi Miura, Toshinori Ozaki, Yutaka Yoshida, Yoshiaki Takaia, Kaname Matsumoto, Masashi Mukaida, Ataru Ichinose, Shigeru Horii, Comparative study of carrier concentration and reciprocal space mapping in SmBa2Cu3Oy thin films with high critical current density, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2006.05.006, 445, 689-693, 2006.10, We have reported SmBa2Cu3Oy (Sm123) films prepared using a pulsed laser deposition (PLD) method. In particularly, Sm123 thin films prepared using a low temperature growth technique (LTG) could achieve a high-J(c) in a magnetic field at 77 K comparable to that in a Nb-Ti wire at 4.2 K. In order to clarify a mechanism of high-J(c) in LTG-Sm123 films, we compared an X-ray reciprocal space mapping (RSM) and a carrier concentration in the LTG films with those in PLD films. Although a Sm123 peak split on the RSM which corresponds to an orthorhombic structure, was observed in the PLD films with a thickness of >= 100 nm, the LTG films did not show such split. Further, from an annealing time dependence of the carrier concentration, a carrier injection into the LTG films tended to be difficult as compared to that into the PLD films. These facts imply that the LTG technique gives a high crystallinity. Therefore, we concluded that one of reasons of the high-J(c) in the LTG films was an improvement of crystalline uniformity such as an orientation and a lattice constant. (c) 2006 Elsevier B.V. All rights reserved..
101. T. Horide, K. Matsumoto, Y. Yoshida, M. Mukaida, A. Ichinose, S. Horii, Combined effect of a single grain boundary and artificial pinning centers on the critical current density in a YBa2Cu3O7-delta thin film, APPLIED PHYSICS LETTERS, 10.1063/1.2364186, 89, 17, 2006.10, The combined effect of a single grain boundary and artificial pinning centers (APCs) on the critical current density (J(c)) in YBa2Cu3O7-delta thin films was investigated. The authors decorated the surface of a 5 degrees-tilt bicrystal SrTiO3 substrate with Y2O3 nanoislands to introduce APCs into the film. J(c) of the bicrystal YBa2Cu3O7-delta film with APCs was measured in various magnetic fields. The APCs improved J(c) in high magnetic fields, but not in low magnetic fields due to the existence of the grain boundary. The limiting mechanism of J(c) in the bicrystal film containing APCs is discussed based on the experimental results. (c) 2006 American Institute of Physics..
102. Masashi Miura, Yusuke Ichino, Yutaka Yoshida, Yoshiaki Takai, Kaname Matsumoto, Ataru Ichinose, Shigeru Horii, Masashi Mukaida, Addition of low-Tc nanoparticles dispersions to enhance flux pinning of Sm1+xBa2-xCu3Oy films, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2006.04.060, 445-448, 1-2, 643-647, 2006.10, We have fabricated epitaxial films of high-Jc SmBCO using a low-temperature growth technique (LTG). The angular dependence of Jc and composition analysis showed that the LTG-SmBCO films included nanosize low-Tc phases within the high-Tc matrix, the LTG-SmBCO films showed Jc = 0.28 MA/cm2 (77 K, B∥c, B = 5 T). However, number density of low-Tc phase is still less than the amount which is desired for complete flux-pinning at high-magnetic field. We deposited LTG-SmBCO including 1.4-2.8 vol.% of low-Tc nanoparticles. The films with 1.4 vol.% nanoparticles showed Jc = 0.37 MA/cm2 (77 K, B∥c, B = 5 T) and 0.10 MA/cm2 (77 K, B∥c, B = 8 T). We speculated that the behaviors of the Jc-B at high-magnetic field depend not only on distribution and size of low-Tc regions, but also the Sm/Ba composition within the low-Tc regions. © 2006 Elsevier B.V. All rights reserved..
103. P. Mele, K. Matsumoto, T. Horide, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, YBa2Cu3O7-x+YSZ mixed films with enhanced critical current densities in magnetic field, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2007.02.026, 463, 653-656, 2007.10, YBa2Cu3O7-x, + YSZ (YBCO + YSZ) mixed films were prepared on SrTiO3/MgO substrates by pulsed laser deposition (PLD) from a YBCO target with thin YSZ sector on the top of the target. In comparison with a pure YBCO film, the J(c) at 77 K for mixed YBCO + YSZ thin film was enhanced from 1.46 MA/cm(2) to 1.95 MA/cm(2) (self-field) and from 0.09 MA/cm(2) to 0.28 MA/cm(2) (B-parallel to c B = 5 T) even when both films were prepared on the same deposition conditions. In the YSZ-added sample, the angular dependence of J(c) shows a broad peak at B-parallel to c due to the flux pinning by c-axis correlated defects. Consistently, elongated nanorods grown in the direction parallel to c-axis were observed in cross-sectional TEM images. (C) 2007 Elsevier B.V. All rights reserved..
104. T. Horide, K. Matsumoto, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, Vortex pinning by gold nanorods in GdBa2Cu3O7-delta thin films, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 10.1109/TASC.2007.899348, 17, 2, 3729-3732, 2007.06, Gold nanorods were introduced into GdBa2Cu3O7-delta (GdBCO) thin films to form artificial pinning centers. The incorporation of gold nanorods into the GdBCO films was achieved simply by attaching gold sheets to a GdBCO target in the pulsed laser deposition process. Transmission electron microscopy observation showed that gold nanorods grew parallel to the c-axis of the GdBCO films. Small angle X-ray scattering and scanning electron microscopy results indicated that matching field, B-Phi was increased with the amount of supplied gold. J(c) - B characteristics in the field aligned with the c-axis at 50 and 65 K exhibited an anomalous shoulder ("peak effect") around at Bp, and the peak position was not dependent on the temperature. This suggests that the "peak effect" was originated from the matching effect between vortices and the gold nanorods..
105. K. Yamada, N. Mori, K. Tada, T. Tanaka, R. Teranishi, M. Mukaida, S. Toh, K. 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, 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. © 2007..
106. T. Horide, K. Matsumoto, Y. Yoshida, M. Mukaida, A. Ichinose, S. Horii, The limitation mechanism of J(c)-theta characteristics in YBa2Cu3O7-x thin film with a single low angle grain boundary, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2007.01.047, 463, 678-681, 2007.10, The angular dependencies of critical current density (J(bc)) in a YBa2Cu3O7-x film on a bicrystal SrTiO3 substrate were measured. At low magnetic field, J(bc) was limited by the low angle grain boundary (LAGB), regardless of the angle, theta between the c-axis and magnetic field. However, the limitation mechanism of J(bc)-theta curves changed at kink positions in high magnetic field. The vortex pinning in the grains determined J(bc) for low theta, but J(bc) at high theta was still limited by the LAGB. The crossover of J(bc) limitation mechanism is discussed to understand the angular dependence of critical current in coated conductors. (C) 2007 Elsevier B.V. All rights reserved..
107. H. Kai, M. Mukaida, S. Horii, A. Ichinose, R. Kita, S. Kato, K. Matsumoto, Y. Yoshida, R. Teranishi, K. Yamada, N. Mori, Superconducting properties and microstructure of PLD-ErBa2C3O7-delta film with BaNb2O6, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2007.04.273, 463, 895-899, 2007.10, We report superconducting properties and microstructures of a ErBa2CU3O7-delta (ErBCO) film with 1.5 wt% BaNb2O6 (BNO) grown by pulse laser deposition (PLD) on a SrTiO3 (STO) substrate. The BNO was introduced into the ErBCO film as an artificial pinning center. Nano-rods originated in the BNO-doping and some particulate defects were clearly observed in transmission electron microscopy (TEM) images of the ErBCO film. The ErBCO film with BNO-doping (BNO + ErBCO) had almost the same critical temperature (T-C) as that of a pure ErBCO film. On the other hand, the BNO + ErBCO film showed less critical current density (J(C)) than that of the pure ErBCO film. The angular peaks for H vertical bar vertical bar c-axis on J(C)-B-theta curves were not confirmed under all the measured external magnetic fields. X-ray diffraction analysis indicated the high orientation to the both c-axis and in-plane for the obtained film. However, the low surface flatness was confirmed by the TEM and atomic force microscopy (AFM) observation. (C) 2007 Elsevier B.V. All rights reserved..
108. S. Yasunaga, M. Mukaida, S. Horii, R. Kita, S. Kato, A. Ichinose, Y. Yoshida, K. Matsumoto, R. Teranishi, K. Yamada, N. Mori, Pulsed laser deposition of ErBa2Cu3O7-delta films with BaZrO3 nano-particles by using a novel target, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2007.04.272, 463, 900-903, 2007.10, We fabricated an ErBa2Cu3O7-(delta) (ErBCO) thin film with BaZrO3 (BZO) doping (BZO + ErBCO) on a SrTiO3 (STO) substrate by a pulsed laser deposition (PLD) method using a novel target which consists of two parts. One is ErBCO for a superconducting phase, the other is rectangular shaped BZO for pinning centers. From an X-ray diffraction (XRD) pattern, the ErBCO film was c-axis oriented and in-plane aligned on the STO substrate. Microstructures of the BZO + ErBCO film were observed by a transmission electron microscope (TEM). In the TEM image, nano-particles of BZO were observed in the film, not nano-rods. This result means that the novel target enables to dope BZO nano-particles into the film without any target changing. From the TEM image and thickness of the sample, a volume percentage of BZO nano-particles is calculated to be 7.3 vol%. It is almost the same to the calculated value from the percentage of laser irradiating area. (C) 2007 Elsevier B.V. All rights reserved..
109. Kazuhiro Yamada, Ataru Ichinose, Yoshitsugu Tomokiyo, Yuki Shingai, Kaname Matsumoto, Yutaka Yoshida, Shigeru Horii, Ryusuke Kita, Shoichi Toh, Kenji Kaneko, Nobuyuki Mori, Masashi Mukaida, Moire fringe analysis of BaZrO3 nanorods in ErBa2Cu3O7-delta films, JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS, 10.1143/JJAP.46.7081, 46, 2, 708-711, 2007.02, Microstructures of BaZrO3 (BZO) doped as artificial pinning centers in ErBa2Cu3O7-delta (ErBCO) films were studied by high-resolution transmission electron microscopy (HR-TEM). BZO-doped ErBCO films were grown by a pulsed laser deposition (PLD) method. In the HR-TEM observation, the presence of nanorods with 10 nm average diameter was confirmed from Moire fringe analysis. The lattice constant of nanorods in the ErBCO was measured using a selected area electron diffraction pattern (SAEDP) as 0.416 nm, which was in good agreement with the lattice constant of BZO, 0.419 nm, provided by X-ray diffraction data. Moire fringes were observed in both cross-sectional-view and plan-view of the HR-TEM images. The distances of the Moire fringes were 2.07, 3.22, and 3.05 nm, and which corresponded to the 200, 006, and 110 reflections of the ErBCO matrix and the 200 002, and 110 reflections of nanorods, respectively. It is suggested that BZO disperses in ErBCO film as nanorods..
110. Ataru Ichinose, Masashi Mukaida, Shigeru Horii, Ryusuke Kita, Kaname Matsumoto, Yutaka Yoshida, Microstructures of high-TC superconducting films introduced zero-dimensional and one-dimensional artificial pinning centers, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2007.898168, 17, 2, 3701-3704, 2007.06, Artificial pinning centers have been introduced into high-Tc superconducting films in order to improve the Jc at 77 K and magnetic fields. The dimensionality of artificial pinning centers has an important role in improving Jc against the magnetic field direction. The one-dimensional artificial pinning centers, such as dislocations and nanorods, are much effective on the B//c-axis. However, pinning centers with magnetic angular independences are much important for practical use. Then, a new concept of zerodimensional artificial pinning centers is applied to high-Tc superconducting films, which is local superconductivity disappearance resulting in the substitution of 3d-transit ion elements such as Zn or Co for Cu. We have no clear evidence of element substitution from microstructural observations. However, the magnetic field angular independences in a wide region except the B//a-axis are revealed in a Zn-doped film, which probably results form zero-dimensional pinning centers. Unexpected magnetic field angular dependences are also revealed, indicating the existence of other pinning centers except zero-dimensional pinning centers. It is found that unexpected defects, such as c-axis-correlated defects or stacking faults, are induced by 3d-transition element substitution. © 2007 IEEE..
111. A. Ichinose, M. Mukaida, P. Mele, T. Horide, K. Matsumoto, R. Kita, Y. Yoshida, S. Horii, Microstructures of BaZrO3-doped ErBa2Cu3Oy films fabricated by different BaZrO3 supply, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2007.04.262, 463, 657-660, 2007.10, ErBa2Cu3Oy films including BaZrO3 are deposited using three types of targets by PLD to realize the self-oriented growth of BaZrO3 nanorods. Microstructures of the obtained films are observed using a transmission electron microscope (TEM). On the basis of the cross-sectional TEM images, the growth mechanism of the BaZrO3 nanorods is discussed. When about a half of BaZrO3-monolayer is added, it is found that the BaZrO3 is not widely segregated to BaZrO3 region and no BaZrO3 region on the ErBa2Cu3Oy surface but the BaZrO3 is homogeneously distributed with approximately 10 nm periods on the ErBa2Cu3Oy surface. As a result, the crystal stress due to the differences of crystal length between the ErBa2Cu3Oy and BaZrO3 are introduced for every 10 nm to the films. This behavior is probably the origin of the self-oriented growth of BaZrO3 nanorods. (C) 2007 Elsevier B.V. All rights reserved..
112. Ataru Ichinose, Kazuaki Naoe, Tomoya Horide, Kaname Matsumoto, Ryusuke Kita, Masashi Mukaida, Yutaka Yoshida, Shigeru Horii, Microstructures and critical current densities of YBCO films containing structure-controlled BaZrO3 nanorods, Superconductor Science and Technology, 10.1088/0953-2048/20/12/010, 20, 12, 1144-1150, 2007.12, BaZrO3 nanorods are known to be effective pinning centers as c-axis-correlated pinning centers. Furthermore, BaZrO3 nanorods in REBa2Cu3Oy (RE: rare-earth element) films are formed by self-assembled stacking of BaZrO3 using a target mixture of a superconductor and BaZrO3 for pulsed-laser deposition, which is a very easy fabrication technique. The density of BaZrO3 nanorods in YBa2Cu3Oy (YBCO) films can be controlled by varying the BaZrO3 content in a target. The BaZrO3 addition has two functions for superconductivity
one is the improvement of pinning forces due to the addition of pinning centers and the other is T c degradation. The optimum BaZrO3 addition for J c improvement in magnetic fields is found to be around 3wt% because of a trade-off between the two functions described above. Furthermore, the length of BaZrO3 nanorods is found to be controlled using two types of target: pure YBCO and a mixture of YBCO and BaZrO3. Varying the BaZrO3 nanorod length has an effect on the pinning mechanism. In particular, magnetic field angle dependences of Jc are varied from c-axis-correlated pinning to nearly random pinning by changing the nanorod length. The magnetic field at the crossover of the pinning mechanism seems to be adjusted by the BaZrO3 nanorod length. © IOP Publishing Ltd..
113. Masashi Mukaida, Tomoya Horide, Yuki Shingai, Ataru Ichinose, Kaname Matsumoto, Shigeru Horii, Ryusuke Kita, Yutaka Yoshida, Satoshi Awaji, Kazuo Watanabe, Ryo Teranishi, Kazuhiro Yamada, Nobuyuki Mori, Microstructure and JQ characteristics of Er123 films with artificial pinning centers, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2007.899122, 17, 2, 3688-3691, 2007.06, Critical current density and surface resistance are evaluated for dilute Zn substituted high quality ErBa2Cu3O7-δ films. Dilute Zn substituted ErBa2Cu3O7-δ films are grown on SrTiO3 substrates by a pulsed laser deposition technique. Targets used in the experiments are un-substituted, 0.3at. %, 0.5at.%, 1.0at.% and 10at.% Zn substituted ErBa2Cu3O 7-δ ceramics. Crystal structures, field angular dependence of critical current density and surface resistance are evaluated. Zn substituting into YBa2Cu3O7-δ has been studied for understanding the origin of oxide superconductivity with substituting level of several %. In this study, dilute Zn below 1.0 at.% is mainly adopted. Further substitution reduces its critical temperature. We intended to introduce zero-dimensional superconductivity killer atoms into CuO2 plane as artificial pinning centers. The obtained Zn substituted ErBa2Cu 3O7-δ films are c-axis oriented without peaks from other phases. The sharp drop temperature of surface resistance decreases as the Zn substitution. However, the surface resistance at a low temperature around 20K is almost the same among the ErBa2Cu3O 7-δ films with different Zn substitution. We also measured the field angular dependence of critical current density of the Zn substituted ErBa2Cu3O7-δ films. There are no strong angular dependences. Dilute zinc substitution increases critical current density for almost of all directions. However, in a high magnetic field of several tesla, pinning force around the field direction of a-axis is enhanced. Double introduction of one dimensional artificial pinning centers such as BaZrO 3 nano-rods and zero dimensional artificial pinning centers is thought to be very effective for increasing critical current density for power cable applications. © 2007 IEEE..
114. T. Horide, K. Matsumoto, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, Matching field effect of the vortices in GdBa2Cu3O7-delta thin film with gold nanorods, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 10.1088/0953-2048/20/4/001, 20, 4, 303-306, 2007.04, Critical current density (J(c)) and irreversibility field (B-irr) were measured for a GdBa2Cu3O7-delta film with gold nanorods which were elongated along the c-axis of the film. The crossover from the single vortex pinning to the plastic pinning region occurred near B-Phi at 10 K. The 'peak effect' in the J(c) - B characteristics at 50 - 82 K and the kink in the B-irr - T curve (T-irr = 87.4 K) were observed near B-Phi (= 0.43 T), when the magnetic fields were applied parallel to the c-axis of the film. The matching field effects have significant roles to determine the behaviours of the vortices in the REBa2Cu3O7-delta ( RE: Y, Gd, Sm, etc) films with correlated pinning centres, like nanorods, regardless of temperature..
115. T. Horide, K. Matsumoto, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, Magnetic-field-induced crossover from flux-flow to Josephson-junction behavior in a highly transparent weak link, PHYSICAL REVIEW B, 10.1103/PhysRevB.75.020504, 75, 2, 2007.01, Magnetic-field-induced Josephson-junction (JJ) behavior in a highly transparent weak link was observed at the 5 degrees tilt low angle grain boundary (LAGB) in a YBa2Cu3O7-delta film. The magnetic field dependence of current density-voltage curves showed that Abrikosov Josephson (AJ) vortices exist in the LAGB. Both JJ and flux-flow (FF) behaviors were observed in a single LAGB depending on the temperature and magnetic field. The crossover from FF to JJ arose from the spread of the phase variation along the junction when the AJ vortex cores overlapped at B-*=phi(0)/(4.4l)(2), where l is the characteristic length of AJ vortex..
116. S. Horii, K. Yamada, H. Kai, A. Ichinose, M. Mukaida, R. Teranishi, R. Kita, K. Matsumoto, Y. Yoshida, J. Shimoyama, K. Kishio, Introduction of c-axis-correlated 1D pinning centers and vortex Bose glass in Ba-Nb-O-doped ErBa2Cu3Oy films, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 10.1088/0953-2048/20/12/005, 20, 12, 1115-1119, 2007.12, We report the effectiveness of barium niobate as a needle-type vortex pinning center, as well as a change in the vortex state in Ba-Nb-O(BNO)-doped ErBa2Cu3Oy thin films. BNO doping was effective for improving critical current properties for a magnetic field direction parallel to the c axis of a matrix film and induced the generation of columnar defects with diameters of 5-25 nm. The irreversibility lines were also changed by the BNO doping and were similar to those of heavy-ion-irradiated YBa2Cu3Oy crystals in which the vortex Bose glass state was induced. It is suggested that the characteristic field relevant to crossover from the Bose glass to collective pinned glass depends on the BNO doping level. There is a possibility that Ba-based perovskite-type oxides promote the formation of nanorods universally and these nanorods play the role of one-dimensional c-axis-correlated pinning centers..
117. P. Mele, K. Matsumoto, T. Horide, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, Insertion of nanoparticulate artificial pinning centres in YBa2Cu3O7-x films by laser ablation of a Y2O3- surface modified target, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 10.1088/0953-2048/20/7/006, 20, 7, 616-620, 2007.07, YBa2Cu3O7-x + Y2O3 ( YBCO + Y2O3) mixed films were prepared on SrTiO3/MgO substrates by pulsed- laser deposition from a YBCO target with a thinY(2)O(3) sector on the top. The pinning properties for the mixed YBCO + Y2O3 thin film were strongly enhanced, especially at the temperatures lower than 77 K: the maximum global pinning forces FP for the Y2O3 doped sample are 7.8 GNm(-3) near 2 T at 77 K, 54.5 GN m(-3) near 4 T at 65 K, and 189 GN m(-3) near 9 T at 40 K. In the Y2O3-added samples, except for the B parallel to ab plane configuration, the angular dependence of J(c) showed a plateau, due to the flux pinning by isotropic pinning centres. Y2O3 nanoparticles randomly dispersed inside the YBCO matrix were consistently observed in the cross- sectional TEM images..
118. N. Mori, Y. Nakahara, K. Ogi, M. Mukaida, In situ observation and analysis of faceted crystal growth process in REBCO superconductive oxide, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2007.05.003, 463-465, 330-334, 2007.10, To clarify the nucleation and growth process of 123 crystals, growth of faceted RE123 (REBa2Cu3O7-X, RE = Nd, Sm, Gd, Y) crystals was observed in situ on MgO(1 0 0) by using high temperature optical microscope with zoom lens. RE123 crystals nucleated and grew at each undercooling (ΔT = 13-50 K). Growth rate (u) and incubation time (tinc) for nucleation were obtained from the relationship between the position of faceted interface and time (t). u increased with increasing Δ Tr2, where ΔTr = ΔT/Tp, Tp was peritectic temperature. Nucleation rate (Iv) was obtained from the relationship between the number of nucleated crystals (n) and time. Iv increased with increasing of exp (- B / Δ Tr2), where B was a constant. Both u and Iv under a fixed ΔT increased with increasing Tp: u(Nd123) >
u(Sm123) >
u(Gd123) and Iv(Nd123) >
Iv(Sm123) >
Iv(Gd123) for Tp(Nd123) >
Tp(Sm123) >
Tp(Gd123) in Ar-1%O2 atmosphere. © 2007 Elsevier B.V. All rights reserved..
119. Ryo Teranishi, Junko Matsuda, Koichi Nakaoka, Teruo Izumi, Yuh Shiohara, Nobuyuki Mori, Masashi Mukaida, High production rate process of YBCO coated conductors by TFA-MOD process, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2007.899412, 17, 2, 3317-3320, 2007.06, Influence of process conditions including water vapor partial pressure, gas flow rate and total annealing pressure on YBa2Cu3O 7-y (YBCO) film growth has been investigated in order to clarify the YBCO growth mechanism and to increase the growth rate. YBCO films have been fabricated on a LaAlO3 substrate by metalorganic deposition (MOD) process using trifluoroacetates (TFA) as a solute source. It was found that the processing parameters such as high water partial pressure, high diffusion constants due to low total pressure, and high gas flow rate affect the YBCO growth rate. Furthermore, it was empirically suggested that the growth rate of the YBCO film was in proportion to both the square root of water partial pressure and gas flow rate and was in inverse proportion to the one sixth power of the total pressure. The YBCO growth rate of about 2 times as fast as the previous condition was achieved with high performance by optimizing the process parameters. © 2007 IEEE..
120. R. Kita, T. Nakamura, A. Ichinose, O. Miura, K. Matsumoto, Y. Yoshida, M. Mukaida, S. Horii, Growth of GdBa2Cu3Oy films prepared by BaF2 process without water vapor, MODERN PHYSICS LETTERS B, 10.1142/S0217984907013705, 21, 21, 1377-1382, 2007.09, We have investigated the influences of the heating rate and film thickness on the growth of GdBa2Cu3Oy (GBCO) thin films prepared by the BaF2 ex-situ process without water vapor. Critical current density (J(c)) and surface morphology of the GBCO films were improved by increasing the heating rate during growth from 30 to 50 degrees C/min. The GBCO films prepared by the heating rate of 50 degrees C/min had the maximum J(c) of 2.1 MA/cm(2). The J(c) value of the GBCO films was about 2 MA/cm(2) up to 200 nm, and decreased to 0.92 MA/cm2 at 400 nm..
121. P. Mele, K. Matsumoto, T. Horide, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, Fabrication of thick YBa2Cu3O7-X films on optimized SrTiO3 buffered-MgO single crystals, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 10.1109/TASC.2007.897422, 17, 2, 3713-3716, 2007.06, In this work, we studied the optimum deposition conditions for SrTiO3 (STO) buffers deposited on MgO single crystals substrates by PLD method. We found that 120 nm thick STO films, deposited at 730 degrees C, present the smoothest surface and a minimum FWMH of the (002) reflection. High quality, smooth and free-crack YBa2Cu3O7-delta, (YBCO) thick superconducting films have then been fabricated using a deposition temperature of 800 degrees C on STO-buffered MgO substrates. A 373 nm thick YBCO/STO/MgO film can carry current densities J(c) (77 K, 0 T) of 1.4 MA/cm(2) and J(c) (77 K, 5 T) of 0.14 MA/cm(2). The J(c) in high field overcomes the current transported in same experimental conditions by 180 nm thick YBCO film grown on Y2O3-decorated STO single crystal. For 1350 nm thick YBCO/STO/MgO film the J(c) (77 K, 0 T) is about 0.8 MA/cm(2) and J(c) (77 K, 5 T) is 0.09 MA/cm(2)..
122. T. Nakamura, R. Kita, O. Miura, A. Ichinose, K. Matsumoto, Y. Yoshida, M. Mukaida, S. Horii, Fabrication of GdBa2Cu3O gamma films by metal-organic deposition using metal-naphthenates, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2007.04.247, 463, 540-543, 2007.10, GdBa2Cu3Oy (GdBCO) films have been prepared by a metal-organic deposition technique using metal-naphthenates by firing amorphous precursor films on SrTiO3 single-crystal substrates at a low oxygen partial pressure. The surface morphology and superconducting properties of the GdBCO films depended strongly on the carbon content and the intermediate phases in the precursor films and the heating conditions. c-axis oriented GdBCO films with flat surface were observed for the heating condition of calcining at 500 degrees C and firing at 800 degrees C. T-c and J(c) of the GdBCO films were 91.3 K and 0.65 MA/cm(2) at 77 K at self-field, respectively. (C) 2007 Elsevier B.V. All rights reserved..
123. S. Funaki, Y. Yoshida, Y. Ichino, M. Miura, Y. Takai, K. Matsumoto, A. Ichinose, M. Mukaida, S. Horii, Enhancement of dislocation density in YBa2Cy3Oy thin films prepared by low temperature growth technique, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2007.04.261, 463, 644-648, 2007.10, In order to achieve further lower substrate temperature (T,) of YBa2Cu3Oy (YBCO) thin films for coated conductor application, we developed low temperature growth (LTG) It technique. In the LTG II technique, a c-axis oriented (Yb1-xNdx)Ba2Cu3Oy thin layer was deposited on MgO substrate as seed layer at low T-s and then YBCO layer was fabricated on the seed layer at the same T-s. As a result, we achieved that the LTG II-YBCO thin films showed complete c-axis orientation at lower T-s than that for obtaining C-axis oriented PLD-YBCO thin films by 15 degrees C, and showed a high J(c). We discussed the orientation mechanism of the LTG II-YBCO thin film using a simple nucleation model. (C) 2007 Elsevier B.V. All rights reserved..
124. Toshinori Ozaki, Yutaka Yoshida, Masashi Miura, Yusuke Ichino, Yoshiaki Takai, Kaname Matsumoto, Ataru Ichinose, Shigeru Horii, Masashi Mukaida, Enhancement of critical current in Sm1+xB2-xCu 3Oy multilayer films with the insertion of Sms-rich phase, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2007.899665, 17, 2, 3270-3273, 2007.06, Coated conductors for power applications require REBCO films with high critical currents (Ic). However, REBCO thick films were likely to be a-axis oriented so that Ic was saturated with increasing the film thickness. Previously we reported that Sm-rich (Sm1+xBa 2-xCu3Oy
x = 0.08) films grown at low deposition temperatures on MgO substrates showed the complete c-axis orientation and the large terrace width as compared with SmBCO (Sm1+xBa 2-xCu3Oy
x = 0.04) films. In this study, we will propose a novel multilayer technique in order to suppress the a-axis growth and keep large terrace width. In this technique thin Sm-rich layers are inserted among SmBCO layers. The multilayer structures [Sm - rich/SmBCO] * N (N = 1, 2, 3, ⋯) was fabricated by PLD method on MgO substrates. Although Ic in the SmBCO single layer films at 77 K was saturated at about 350 A/cm-width over the thickness of about 1.3 μm, the SmBCO multilayer films with a thickness of 1.7 μm showed the complete c-axis orientation, and the Ic achieved about 800 A/cm-width at 77 K. We confirmed that the growth of the a-axis oriented regions was suppressed by the Sm-rich layers. It is considered that the Sm-rich layers act as a template layer for maintaining the c-axis orientation, even though the surface temperature decreased with the thickness. © 2007 IEEE..
125. Y. Yoshida, Y. Ichino, M. Miura, T. Ozaki, Y. Takai, K. Matsumoto, A. Ichinose, M. Mukaida, S. Horii, Enhanced superconducting performances in nanostructured SmBCO coated conductor, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2007.03.462, 463, 633-638, 2007.10, We have studied the artificial pinning center (APC) techniques in Sm1+xBa2-xCu3Oy (SmBCO) films deposited on single crystalline substrates. As a result, using the low temperature growth (LTG)-PLD technique, J(c) of 0.28 MA/cm(2) at 77K, B=5T (B parallel to c) was obtained on 700 run thick SmBCO films grown on 50 nm thick SmBCO-seed buffered MgO substrate. Following the successful demonstration of the growth of SmBCO films on single crystalline substrate, the LTG technique was also extended to coated conductor on metal substrates. With the objectives of applying the superconducting magnetic application that operate at liquid nitrogen temperature, we report the Jc in magnetic field and the microstructure of SmBCO coated conductor. PLD-SmBCO with a J(c), of over 0.1 MA/cm(2) at 5 T (B parallel to c, 77 K) were grown on IBAD-YSZ/CeO2 tape, which is higher than YBCO/IBAD. In addition, the J(c), values of the SmBCO coated conductor grown with LTG technique measuring 0.23 MA/m(2) for 5 T of B parallel to c at 77 K are comparable to that of NbTi for 5 T at 4.2 K. From the magnetic field angular dependences of J(c) the anisotropy of the SmBCO film/IBAD tape is small. This performance in SmBCO coated conductor on metal substrate is comparable to the best results of SmBCO films on MgO single crystalline substrates. We discussed about the elemental mapping of the high-J(c) SmBCO coated conductor measured by TEM-EDX. (C) 2007 Elsevier B.V. All rights reserved..
126. P. Mele, K. Matsumoto, T. Horide, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, Enhanced high-field performance in PLD films fabricated by ablation of YSZ-added YBa2Cu3O7-x target, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 10.1088/0953-2048/20/3/023, 20, 3, 244-250, 2007.03, YBa2Cu3O7-x + Y2O3-stabilized ZrO2 (YBCO+YSZ) mixed films were prepared on SrTiO3/MgO substrates by pulsed-laser deposition from a YBCO target with a thin YSZ sector on top. The J(c) at 77 K for the mixed YBCO + YSZ thin film was enhanced. The Jc at 77 K for the pure film and the mixed YBCO + YSZ thin film were 1.46 and 1.95 MA cm(-2) ( self field) ( and 0.09 and 0.28 MA cm(-2) ( B parallel to c, B = 5 T)), respectively, even when both films were prepared using the same deposition conditions. The maximum pinning force of a doped film ( 77 K, B parallel to c) was 15.9 GNm(-3), which is comparable to the value reached by NbTi at 4.2 K. In the YSZ-added sample, the angular dependence of Jc showed a broad peak at B parallel to c due to the flux pinning by the c-axis correlated defects. Elongated nanorods grown parallel to the c axis were consistently observed in the cross-sectional TEM images..
127. Masashi Miura, Yutaka Yoshida, Toshinori Ozaki, Yusuke Ichino, Yoshiaki Tarai, Kaname Matsumoto, Ataru Ichinose, Shigeru Horii, Masashi Mukaida, Enhanced critical current under a magnetic field in Sm1+xB 2-xCu3Oy thick films prepared using low-temperature growth technique, Japanese Journal of Applied Physics, Part 2: Letters, 10.1143/JJAP.46.L807, 46, 33-35, L807-L809, 2007.09, REBa2Cu3Oy films require a high critical current (Ic) under a high magnetic field at 77 K when using power applications. In this study, we fabricated Sm1.04Ba 1.96Cu3Oy (SmBCO) thick films prepared using a low-temperature growth (LTG) technique in order to improve crystal quality and enhance flux pinning. The LTG multilayer thick film using a (SmBCO/Sm-rich layer) × N (N = 1,2,...) multilayer system showed a high crystal quality. Additionally, the LTG multilayer thick film showed not only a high density of dislocations but also low-Tc particles within a high-Tc matrix. Therefore, the LTG multilayer film showed an Ic of 20.6 A/cm-width (77 K, B // c, B = 5 T) and had a thickness of only 1.35 μm and a low anisotropy Ic for the high-magnetic-field direction. These results support to the developing possibility of power devices using a solenoid-type coil. © 2007 The Japan Society of Applied Physics..
128. T. Tanaka, K. Tada, N. Mori, K. Yamada, R. Teranishi, M. Mukaida, Y. Shiohara, T. Izumi, J. Matsuda, Deposition process, microstructure and properties of YBCO film fabricated by advanced TFA-MOD method, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2007.01.041, 463-465, 527-531, 2007.10, The metal organic deposition (MOD) process using trifluoroacetates is expected as a promising method for producing YBCO coated conductors since the high JC performance can be provided by this low cost non-vacuum process. Investigation of the growth mechanism for the YBCO films is important to obtain the high crystal grain alignment for high JC in thick films. In order to clarify the YBCO growth mechanism in detail, we fabricated YBCO films on LaAlO3 (LAO) or CeO2/LAO substrate and investigated the microstructures of the films quenched during the crystallization process. The effects of the crystallization temperature and time on the microstructures of the films and its formation process as well as the JC values were studied. The YBCO growth model during crystallization was proposed according to the observation results of YBCO formation process. © 2007 Elsevier B.V. All rights reserved..
129. T. Ozaki, Y. Yoshida, M. Miura, Y. Ichino, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii, M. Mukaida, Current-carrying property and microstructure of multilayered Sm1+xBa2-xCu3Oy thick films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2007.03.463, 463, 649-652, 2007.10, We have fabricated Sm1+xBa2-xCu3Oy (SmBCO) multilayer (Multi-SmBCO) films with alternating main SmBCO (x = 0.04) layers and additional Sm-rich (x = 0.08) layers. We confirmed that Cu2O precipitates in PLD-SmBCO films increased with increasing film thickness, though those in the Multi-SmBCO films hardly appeared even in thick films. I-c of the Multi-SmBCO film with a 1.7 mu m thickness achieved 800 A/cm-width (J(c) = 4.6 MA/cm(2)) at 77 K. Furthermore, the Multi-SmBCO film showed improved J(c) at all magnetic field, especially, at high-magnetic fields. The enhancement of J(c) in the high-magnetic fields would be related to Sm-rich phase (low-T-c phase) formed by introducing the Sm-rich layers. (C) 2007 Published by Elsevier B.V..
130. S. Horii, A. Ichinose, Y. Ichino, T. Ozaki, Y. Yoshida, K. Matsumoto, M. Mukaida, J. Shimoyama, K. Kishio, Critical current properties and microstructures in impurity-doped ErBa2Cu3Oy films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2007.03.473, 463, 922-926, 2007.10, We report minute doping effects of cobalt on critical current properties and microstructures in ErBa2Cu3Oy (Er I 23)/SrTiO3 thin films. Although critical temperatures (T-c for the Co0.5%-doped Er123 films decreased with substrate temperature (T-s), magnetic-field angular (0) dependence of J(c), for the films grown at lower T, showed clear c-axis peaks. Also from a fact that defects along the c-axis direction were observed in their cross-sectional microstructures, the c-axis peaks were derived from existence of c-axis correlated vortex pinning centers. On the other hand, Tc is almost constant for the change in T, for the Co0.1%-doped Er123 films. Remarkable c-axis peaks were not observed in J(c)-theta curves and, however, J(c)(H vertical bar vertical bar ab)/Jc,(H vertical bar vertical bar c) was decreased compared with that of the pure Er123 films. Namely, minute doping of cobalt showed a reduction effect of electromagnetic anisotropy of the Er123 matrix within the Co-doping levels at which Tc was maintained in similar to 90 K. (C) 2007 Elsevier B.V. All rights reserved..
131. Y. Shingai, T. Numasawa, M. Mukaida, R. Teranishi, R. Kita, A. Ichinose, S. Horii, Y. Yoshida, K. Matsumoto, S. Awaji, K. Watanabe, A. Saito, K. Yamada, N. Mori, Characteristics of ErBa2Cu3O7-delta films with BaWO4 doping, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2007.04.275, 463, 909-913, 2007.10, BaWO4 (BWO) doped ErBa2CU3O7-theta (Er-123) (BWO + Er-123) films are fabricated and their superconducting properties are evaluated. We discuss the effect of BWO doping into Er-123 films on their crystallinity and superconducting properties. The grown BWO + Er-123 films were in-plane aligned and c-axis oriented. We characterize in-plane crystallinity of the films by XRD in-plane rotation measurement (T-scan). The full width at a half maximum of the (p-scan pattern (5(p) of the grown BWO + Er-123 films became wider as increasing BWO doping. The critical temperature (T-CO) of 2.0 wt% BWO + Er-123 films was about 90.5 K. From this result, it was confirmed that the BWO + Er-123 films had as high T-C as pure Er-123 films. Surface resistance (R-S) of the BWO + Er-123 films was degraded comparing to that of a pure Er-123 film. The relationships between critical current density (J(C)) and applied magnetic field (J(C)-B) and the magnetic field angular dependence of J(C) of the grown 2.0 wt% BWO + Er-123 film were evaluated at 77 K. As a result, it is confirmed that the JC of the Er-123 films in magnetic fields decreased by the BWO doping comparing to that of the pure Er-123 film. However, it was also confirmed that the 2.0 wt% BWO + Er- 123 film had weak pining centers along the c-axis of Er-123 films. From the result of a cross-sectional transmission electron microscope (TEM) image, some rod structures were observed in the 2.0 wt% BWO + Er-123 films. The diameter of the rod was about 20 nm. These rods grew along the c-axis of Er- 123 films from the substrate to the surface of the film. (C) 2007 Published by Elsevier B.V..
132. M. Takamura, M. Mukaida, Y. Shingai, R. Teranishi, K. Yamada, N. Mori, S. Horii, A. Ichinose, R. Kita, S. Kato, K. Matsumoto, Y. Yoshida, A new approach to a two-dimensional artificial pinning center, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2007.04.274, 463, 904-908, 2007.10, A multilayer alternately stacked a-axis oriented YBa2CU3O7-delta and PrBa2Cu3O7-delta (Y123/Pr123 multilayer) has been grown on a SrLaGaO4 substrate with a Gd2CUO4 buffer layer by pulsed laser deposition. We used an Y123 target that contains a Pr123 sector for obtaining the Y 123/Pr 123 multilayer. The multilayer structure of the obtained film was confirmed by a transmission electron microscope. In magnetic field (B) angular dependences of critical current density (J(C)) (J(C)-B-theta curves), J(C) peaks were observed at B vertical bar vertical bar a-axis and B vertical bar vertical bar c-axis of the Y123/Pr123 multilayer. Peaks at B vertical bar vertical bar c-axis are absent in J(C)-B-theta curves of pure a-axis oriented Y123 films. Therefore, peaks at B vertical bar vertical bar c-axis in J(C)-B-theta curves of the Y123/Pr123 multilayer are attributed to Pr123 layers. This result indicates that the Y123/ Pr123 multilayer has c-axis-correlated pinning centers. Consequently, it is concluded that Pr 123 layers work as two-dimensional artificial pinning centers with the current direction along the b-axis. (C) 2007 Elsevier B.V. All rights reserved..
133. Paolo Mele, Kaname Matsumoto, Tomoya Horide, Ataru Ichinose, Masashi Mukaida, Yutaka Yoshida, Shigeru Horii, Ryusuke Kita, Ultra-high flux pinning properties of BaMO3-doped YBa 2Cu3O7-x thin films (M = Zr, Sn), Superconductor Science and Technology, 10.1088/0953-2048/21/3/032002, 21, 3, 2008.03, We studied the flux pinning properties of BaZrO3-doped YBa 2Cu3O7-x and BaSnO3-doped YBa 2Cu3O7-x films. We found that BaSnO 3-doped films showed very high global pinning forces, Fp, of 28.3GNm-3 (77K, ) and 103GNm-3 (65K, ), twice that of BaZrO3-doped films. Transmission electron microscopy analysis showed that, in both films, nanorods of the dopant phase were incorporated. The BaSnO3 nanorods were nearly straight but the BaZrO3 nanorods became curved with the increasing film thickness. © 2008 IOP Publishing Ltd..
134. K. Yamada, A. Ichinose, S. Yasunaga, R. Teranishi, M. Mukaida, S. Horii, R. Kita, S. Kato, Y. Yoshida, K. Matsumoto, S. Toh, Transmission electron microscopy analysis of nanorods in BaSnO 3-doped ErBa2Cu3O7-δ films, Japanese Journal of Applied Physics, 10.1143/JJAP.47.899, 47, 2, 899-903, 2008.02.
135. Tomoya Horide, Kaname Matsumoto, Yutaka Yoshida, Masashi Mukaida, Ataru Ichinose, Shigeru Horii, Tilt angle dependences of vortex structure and critical current density at low-angle grain boundaries in Y Ba2 Cu3 O7-x films, Physical Review B - Condensed Matter and Materials Physics, 10.1103/PhysRevB.77.132502, 77, 13, 2008.04, A tilt angle dependence of vortex structure was studied at low-angle grain boundaries (LAGBs) in Y Ba2 Cu3 O7-x films. The 2°tilt LAGB did not degrade Jc of the film in a self-field, demonstrating the existence of Abrikosov vortices at the 2° LAGB. The magnetic field dependence of the flux flow resistance indicated the existence of Abrikosov Josephson vortices at the 5° tilt LAGB. At the 10° tilt LAGB, a Josephson junction behavior was observed in a self-field, indicating the existence of Josephson vortices. The influence of the LAGBs on critical current density was understood based on these vortices. © 2008 The American Physical Society..
136. P. Mele, K. Matsumoto, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, R. Kita, Systematic study of the BaSnO(3) insertion effect on the properties of YBa(2)Cu(3)O(7-x) films prepared by pulsed laser ablation, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 10.1088/0953-2048/21/12/125017, 21, 12, 2008.12, YBa(2)Cu(3)O(7-x) + BaSnO(3) (YBCO + BSO) mixed films with increasing BSO content were prepared on SrTiO(3) substrates by pulsed laser deposition from YBCO + x wt% BSO mixed targets (x = 2, 3, 4, 5, 6, 8 and 9 wt%). Transmission electron microscopy (TEM) images reveal that BSO is incorporated into the YBCO matrix in form of nanorods, whose density and size increase with increasing BSO content. The pinning properties for the mixed YBCO + BSO film were systematically studied. The 4 wt% sample presents the maximum global pinning forces FP at all considered temperatures: 28.3 GN m(-3) near 2 T at 77 K, 103 GN m(-3) near 5 T at 65 K, and > 241 GN m(-3) near 9 T at 40 K..
137. R. Teranishi, S. Yasunaga, H. Kai, K. Yamada, M. Mukaida, N. Mori, T. Fujiyoshi, A. Ichinose, S. Horii, K. Matsumoto, Y. Yoshida, R. Kita, S. Awaji, Superconducting properties of ErBCO films with BaMO3 nanorods (M = Zr and Sn) by pulsed laser deposition, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.065, 468, 15-20, 1522-1526, 2008.09.
138. T. Nakamura, R. Kita, O. Miura, A. Ichinose, K. Matsumoto, Y. Yoshida, M. Mukaida, S. Horii, Superconducting properties of GdBa2Cu3Oy films by metal-organic deposition using new fluorine-free complex solutions, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.070, 468, 15-20, 1542-1545, 2008.09.
139. K. Inoue, Y. Yoshida, Y. Ichino, Y. Takai, K. Matsumoto, A. Ichinose, M. Mukaida, S. Horii, Superconducting properties in magnetic field of (Nd, Eu, Gd)1+xBa2-xCu3Oy thin films prepared by low temperature growth technique, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.257, 468, 15-20, 1611-1614, 2008.09.
140. Yutaka Yoshida, Toshinori Ozaki, Yoshiaki Takai, Kaname Matsumoto, Ataru Ichinose, Shigeru Horii, Masashi Mukaida, Y. Ichino, Progress towards nanostructured SmBCO film for controlling pinning properties, Journal of Physics: Conference Series, 10.1088/1742-6596/97/1/012021, 97, 1, 2008.02, We have studied the artificial pinning center (APC) techniques in Sm 1+xBa2-xCu3Oy (SmBCO) films deposited on single crystalline substrates. As a result, using the Low Temperature Growth (LTG)-PLD technique, Jc of 0.28 MA/cm2 at 77 K, B=5 T (B // c) was obtained on 700 nm thick SmBCO films grown on 50 nm thick SmBCO-seed bufferd MgO substrate. Following the successful demonstration of the growth of SmBCO films on single crystalline substrate, the LTG technique was also extended to coated conductor on metal substrates. With the objectives of applying the superconducting magnetic application that operate at liquid nitrogen temperature, we report the Jc in magnetic field and the microstructure of SmBCO coated conductor. PLD-SmBCO with a Jc of over 0.1 MA/cm2 at 5 T (B // c, 77K) were grown on IBAD-YSZ/CeO 2 tape, which is higher than YBCO/IBAD. In addition, the J c values of the SmBCO coated conductor grown with LTG technique measuring 0.23 MA/cm2 for 5 T of B // c at 77 K are comparable to that of NbTi for 5 T at 4.2 K. From the magnetic field angular dependences of Jc, the anisotropy of the SmBCO film/IBAD tape is small. This performance in SmBCO coated conductor on metal substrate is comparable to the best results of SmBCO films on MgO single crystalline substrates. © 2008 IOP Publishing Ltd..
141. Y. Yoshida, T. Ozaki, Y. Ichino, Y. Takai, K. Matsumoto, A. Ichinose, M. Mukaida, S. Horii, Progress in development of advanced PLD process for high Jc REBCO film, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.082, 468, 15-20, 1606-1610, 2008.09.
142. N. Mori, K. Tada, K. Yamada, R. Teranishi, M. Mukaida, Numerical study on crystal growth process in YBCO film fabricated by TFA-MOD method, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.221, 468, 15-20, 1537-1541, 2008.09, To fabricate high-Jc coated conductor of YBa2Cu3O7-X (1 2 3) film, metal-organic deposition (MOD) process using precursor solution of trifluoroacetates (TFAs) is one of the most promising low cost non-vacuum methods. However, details of the growth process and the mechanism of 123-crystal growth are still unknown. To clarify the growth mechanism of 123-film, the growth processes of 123-crystals were studied by the experimental method and the numerical method. Microstructures of growing 123-crystals were revealed through transmission electron microscopy (TEM) observations of the specimens quenched during the growth of 123-crystals on LaAlO3 (LAO) substrates. The growth process of faceted 123-crystals with various crystal orientations was simulated by the two-dimensional numerical method using c-axis and a-axis growth rate functions. The growth processes and the microstructures of 123-crystals were visualized by the simulation. The meandering of crystal boundaries, overgrowth of preferred oriented crystals, and the effects of initial distributions of nucleated crystals and particles were studied. © 2008 Elsevier B.V. All rights reserved..
143. A. Ichinose, P. Mele, T. Horide, K. Matsumoto, G. Goto, M. Mukaida, R. Kita, Y. Yoshida, S. Horii, Microstructures of REBa2Cu3Oy adding BaZrO3 or BaSnO3, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.085, 468, 15-20, 1627-1630, 2008.09.
144. Hiroyuki Nasu, Yasuji Yamada, Masashi Mukaida, Shugo Kubo, Liquid phase epitaxy of YBa2Cu3O7-δ film on single crystalline MgO and NdGaO3 substrate, Journal of Physics: Conference Series, 10.1088/1742-6596/97/1/012274, 97, 1, 2008.02, YBa2Cu3O7-δ (YBCO) films were deposited by a liquid phase epitaxy (LPE) method on MgO single crystalline substrates that were covered by thin film of pulsed-laser-deposited (PLD) YBCO as a seed layer. The 990°C-deposited LPE film showed c-axis orientation perpendicular to the substrate surface and in-plain two -dimensional alignment. The LPE film contained twin structure with good crystalline perfection and the PLD film showed broad in-plain alignment, meaning lattice constant distribution or lattice distortion. © 2008 IOP Publishing Ltd..
145. P. Mele, K. Matsumoto, T. Horide, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, R. Kita, Incorporation of double artificial pinning centers in YBa2Cu3O7-δ films, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.228, 468, 15-20, 1631-1634, 2008.09.
146. S. Yasunaga, M. Mukaida, A. Ichinose, S. Horii, R. Teranishi, K. Yamada, K. Matsumoto, R. Kita, Y. Yoshida, N. Mori, Growth of BaSnO3 doped ErBa2Cu3O7-δ thin films for high JC applications, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.101, 468, 15-20, 1858-1860, 2008.09.
147. Nobuyuki Mori, Ryo Teranishi, Keisuke Tada, Jiro Yoshida, Kazuhiro Yamada, Masashi Mukaida, Formation of microstructures and continuous heating and time-temperature transformation diagrams of YBa2Cu3O7-x film fabricated by metal organic deposition with trifluoroacetates, JAPANESE JOURNAL OF APPLIED PHYSICS, 10.1143/JJAP.47.7131, 47, 9, 7131-7135, 2008.09, The metal organic deposition (MOD) using a precursor solution of trifluoroacetates (TFA) is known to be a promising low cost nonvacuum process for fabricating a high-J(c) coated conductor of YBa2Cu3O7-x (YBCO or Y123) film. However, the details of the growth process of Y123 crystals are still unknown. To clarify the growth mechanism of Y123 crystals in the film. the growth processes of Y123 crystals were studied experimentally through transmission electron microscopy (TEM) observations of the specimens quenched during the growth of Y123 crystals on LaAlO3 (LAO) substrates, and the continuous heating and tune-temperature transformation (CHT/TTT) diagrams and the growth model of c/a-oriented Y123 crystals were obtained. Furthermore. the growth processes of faceted Y123 crystals with various crystal orientations were simulated by the two-dimensional numerical method using c- and a-axis growth rate functions. The formation processes of microstructures of Y123 crystals were visualized using the growth model and the simulation..
148. T. Ozaki, Y. Yoshida, Y. Ichino, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii, M. Mukaida, Flux pinning properties of Sm1+xBa2-xCu3Oy films with BaZrO3 nanorods fabricated by low-temperature growth technique, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.083, 468, 15-20, 1615-1618, 2008.09.
149. T. Fujiyoshi, M. Haruta, T. Sueyoshi, K. Yonekura, M. Watanabe, M. Mukaida, R. Teranishi, K. Matsumoto, Y. Yoshida, A. Ichinose, S. Horii, S. Awaji, K. Watanabe, Flux pinning properties of REBa2Cu3Oy thin films with BaZrO3 nano-rods, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.155, 468, 15-20, 1635-1637, 2008.09.
150. Fabrication and characterization of BaSnO3-doped NdBa2Cu3O7-δthin film
We fabricated a BaSnO3-doped NdBa2Cu3O7-δfilm on a MgO substrate by a pulsed laser deposition method. We confirmed 00l reflections of NdBa2Cu3O7-δfilm in X-ray diffraction. In the cross-sectional transmission electron microscopy observation of the film, the presence of nanorods with 20 nm with average diameter is confirmed from bright-field images. We confirmed these nanorods contained tin (Sn) by EDS elemental maps. The crystal structure of the nanorod was determined to be cubic perovskite from its selected area electron diffraction pattern. Using the selected area electron diffraction patterns, the lattice constant of the nanorods in the NdBa2Cu3O7-δfilm was calculated to be 0.415 nm which was in good agreement with the lattice constant of BaSnO3of 0.412 nm. © 2008 Elsevier B.V. All rights reserved..
151. Y. Ichino, Y. Yoshida, K. Inoue, S. Funaki, Y. Takai, K. Matsumoto, M. Mukaida, A. Ichinose, S. Horii, Enhancement of critical temperature of LaBa2Cu3Oy thin films by novel film growth technique, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.153, 468, 15-20, 1623-1626, 2008.09.
152. Electrical transport properties of Y123 films with 2-D apcs
Electrical transport properties are discussed for YBa2Cu3O7-δ123) films with 2-dimensional artificial pinning centers (2-D APCs). An Y123/Pr123 multilayer film with TC0of ∼80 K was successfully grown on a SrLaGaO4substrate. In the Y123/Pr123 multilayer film, the a-axis oriented Y123 and Pr123 were stacked alternately on the substrate. JC-θ curves in magnetic fields at 60 K showed a peak at B//c, suggesting that the Y123/Pr123 multilayer films have c-axis correlated pinning centers. The magnetic field dependence of the JC(B//c)/JC(B//a) showed a maximum around the calculated matching field of the Y123/Pr123 multilayer film. The JC(B//c)/JC(B//a) decreased above the matching field. © 2008 Elsevier B.V. All rights reserved..
153. H. Kai, M. Mukaida, R. Teranishi, N. Mori, K. Yamada, S. Horii, A. Ichinose, R. Kita, K. Matsumoto, Y. Yoshida, S. Awaji, K. Watanabe, M. Namba, T. Fujiyoshi, Effects of growth temperature for superconducting properties and microstructures of PLD-ErBa2Cu3O7-δ film with BaNb2O6, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.100, 468, 15-20, 1854-1857, 2008.09.
154. A. Mitani, R. Teranishi, K. Yamada, N. Mori, M. Mukaida, T. Kiss, M. Inoue, Y. Shiohara, T. Izumi, K. Nakaoka, J. Matsuda, Effect of fabrication conditions on crystalline of SmBCO films fabricated by TFA-MOD method, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.066, 468, 15-20, 1546-1549, 2008.09, Metal organic deposition using trifluoroacetates is expected as a method for YBCO coated conductors since this method can provide high superconducting properties and is a cost-effective process with non-vacuum system. Recently, REBCO coated conductors, which has high critical properties, have attracted considerable attention. However, there are some problems to optimize fabrication conditions of REBCO films with this method. In this study, we fabricated SmBCO films by TFA-MOD method and investigated the effect of fabrication conditions on crystalline. We focused especially on a starting temperature (T1) of inlet moisture in calcination step and O2 gas concentration in crystallization step. Flat surfaces were obtained for the calcined films at both T1 = 300 °C and 350 °C compared with that at 200 °C. One possible reason for this worse morphology at T1 = 200 °C might be a length of a reaction time between moisture and coated film. When moisture is supplied from low temperature for long time, water could react easily to the fluoride which is contained a lot in the coated film
as a result, more HF gas is generated from the film. The crystalline was also improved for the SmBCO films calcined at over T1 = 300 °C. Furthermore, the film calcined at T1 = 350 °C was crystallized under the condition that O2 gas concentration was varied between 0.2 ppm and 1000 ppm. The degree of c-axis orientation depends on oxygen partial pressure and the highest c-axis oriented SmBCO film was obtained in the case of 10 ppm. © 2008 Elsevier B.V. All rights reserved..
155. J. Yoshida, K. Tada, T. Tanaka, N. Mori, K. Yamada, R. Teranishi, M. Mukaida, T. Kiss, M. Inoue, Y. Shiohara, T. Izumi, K. Nakaoka, J. Matsuda, Effect of calcination conditions on microstructures and Jc of YBCO films fabricated by TFA-MOD method, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.254, 468, 15-20, 1550-1553, 2008.09, YBCO films were grown on LaAlO3 substrates by a metal organic deposition using trifluoroacetates (TFA-MOD). In the TFA-MOD method, a starting solution is coated on a substrate firstly, and then the coated film is calcined to form precursor and finally the precursor film is crystallized to form superconducting YBCO film. In this study, the effects of calcination conditions such as temperature on the microstructures and Jc properties of the YBCO films were studied. In the calcination step, spin coating and calcination were repeated three times for obtaining thick film under the maximum temperatures of 400-500 °C. The prepared precursor films were crystallized at a constant condition. The Jc values of the films calcined at 500 °C after at 400 °C × 2 times, 400 °C × 3 times and 500 °C × 3 times were about 1.49 MA/cm2, 2.52 MA/cm2 and 1.47 MA/cm2, respectively. Jc depended strongly on the calcination temperature. The cross-sectional TEM images showed that the YBCO film calcined at 400 °C × 3 times had less pores than the others. Optimization of the calcination temperature was important to suppress the formation of large precipitates in precursor film, resulting in the suppression of the large pores in the YBCO film. © 2008 Elsevier B.V. All rights reserved..
156. N. Mori, M. Mukaida, R. Teranishi, K. Yamada, T. Tanaka, K. Tada, Crystal growth process of Y123 film fabricated by modified TFA-MOD process, Journal of Physics: Conference Series, 10.1088/1742-6596/97/1/012061, 97, 1, 2008.02, Modified metal-organic deposition (MOD) process using precursor solution of trifluoroacetates (TFA) for Y and Ba and F-free salt for Cu is one of the most promising low cost non-vacuum methods to fabricate the coated conductor of YBa2Cu3O7-X (Y123) film with high critical current density. Since Y123 phase grows in the precursor film by the release of HF with supplying H2O, liquid/gas evolution affects the growth process, microstructure and properties of Y123 film. However, details of the growth mechanism of Y123 crystals are still unknown. To clarify the growth mechanism of Y123 film, the growth process of Y123 crystal was studied by the experimental method and the numerical method (FDM analysis). The quenching experiments during the growth of Y123 crystals on LaAlO3 (LAO) and/or CeO2/LAO substrates revealed the microstructures of growing Y123 crystals through TEM observations. The growth model for Y123 crystals in YBCO film with some process-controlling parameters was obtained on the basis of the experimental results. The growth processes of faceted Y123 crystals with various crystal orientations were simulated by the two-dimensional numerical method using c-axis and a-axis growth rate functions, and the effects of initial distributions of nucleated crystals and particles were discussed. © 2008 IOP Publishing Ltd..
157. R. Teranishi, A. Mitani, K. Yamada, N. Mori, Y. Hisatsune, M. Mukaida, M. Inoue, T. Kiss, K. Nakaoka, J. Matsuda, T. Izumi, Y. Shiohara, Crystal grains alignment of SmBCO film by advanced TFA-MOD method, Journal of Physics: Conference Series, 10.1088/1742-6596/97/1/012171, 97, 1, 2008.02, We grew SmBa2Cu3O7-y (SmBCO) films on LaAlO3 (LAO) single crystalline substrates by an advanced TFA-MOD method and discussed the effects of process conditions such as oxygen partial pressure in the crystallization step on the crystal grains alignment of SmBCO film. Oxygen partial pressure affected strongly on the orientation of SmBCO film. Formation of a-axis crystal grains of the SmBCO was suppressed, and, at the same time, c-axis crystal grains of the SmBCO increased with decreasing the oxygen concentration. © 2008 IOP Publishing Ltd..
158. S. Funaki, Y. Ichino, Y. Yoshida, K. Inoue, Y. Takai, K. Matsumoto, M. Mukaida, A. Ichinose, S. Horii, Critical temperature of LaBa2Cu3Oy thin films by vapor-liquid-solid growth technique improved by the composition ratio in liquid phase, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.072, 468, 15-20, 1575-1578, 2008.09.
159. S. Horii, T. Horide, K. Matsumoto, T. Ozaki, Y. Ichino, M. Mukaida, Y. Yoshida, A. Ichinose, J. Shimoyama, K. Kishio, Critical current properties at low angle grain boundaries in ErBa2Cu3Oy films, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.172, 468, 15-20, 1670-1673, 2008.09.
160. K. Yamada, A. Ichinose, S. Horii, H. Kai, R. Teranishi, M. Mukaida, R. Kita, S. Kato, Y. Yoshida, K. Matsumoto, S. Toh, Characterization of nanorods in BaNb2O6-doped Er123 films revealed by cross-sectional transmission electron microscopy, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2008.05.157, 468, 15-20, 1638-1642, 2008.09, microstructures of BaNb2O6-doped as artificial pinning centers in Er123 films were studied by cross-sectional transmission electron microscopy. BaNb2O6-doped Er123 films were grown by a pulsed laser deposition technique. In the cross-sectional transmission electron microscopy observation, the presence of nanorods with 5 nm-25 nm diameter, which contain niobium, was confirmed from bright-field images and energy-dispersive X-ray spectroscopy elemental map images, respectively. The crystal structure of the nanorod was determined to be cubic perovskite from selected area electron diffraction patterns by comparing with that of the SrTiO3 Substrate, The axial length of nanorods in the Er123 film was calculated selected area electron diffraction patterns, as 0.841 nm, which is in good agreement with the axial length of Ba(Er0.5Nb0.5)O-3, 0.8427 nm, provided by X-ray diffraction data. Furthermore, parallel Moire fringes were observed in the bright-field images, and the relationships between the lattice planes and Moire fringes were investigated. The spacings of the Moire fringes were 3.6 nm, and 2.3 nm, which correspond to the 006 and 200 reflections for Er123 and the 004 and 400 reflections of the nanorods, respectively. It is confirmed for the first time that BaNb2O6-doped into the Er123 him transforms to Ba(Er0.5Nb0.5)O-3 nanorods with a cubic perovskite structure. (C) 2008 Elsevier B.V. All rights reserved..
161. K. Yuki, H. Kai, M. Mukaida, S. Horii, R. Kita, A. Ichinose, Y. Yoshida, K. Matsumoto, R. Teranishi, K. Yamada, N. Mori, A research for controlling nanorod diameter in BaNb2O6 doped REBa2Cu3O7-δ films, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2008.05.102, 468, 15-20, 1861-1863, 2008.09.
162. M. Takamura, M. Mukaida, S. Horii, A. Ichinose, R. Kita, S. Kato, K. Matsumoto, Y. Yoshida, M. Namba, S. Awaji, K. Watanabe, R. Teranishi, K. Yamada, N. Mori, Y. Hisatsune, A novel 2-dimensional artificial pinning center, Journal of Physics: Conference Series, 10.1088/1742-6596/97/1/012153, 97, 1, 2008.02, To increase critical current density (JC) in magnetic fields (B) parallel to the c-axis, 2-dimensional artificial pinning centers (APCs) are introduced into YBa2Cu3O7-δ (Y123) films. Multilayer films alternately stacked a-axis oriented Y123 and Pr123 (Y123/Pr123 multilayer films) have been grown on SrLaGaO4 substrates by pulsed laser deposition. Magnetic field angular dependences of the JC showed peaks not only in B // a-axis but also in B // c-axis of the Y123/Pr123 multilayer films. This result indicates that the Y123/Pr123 multilayer films have c-axis-correlated pinning centers. Consequently, it is suggested that the Pr123 layers act as 2-dimentional APCs. © 2008 IOP Publishing Ltd..
163. P. Mele, K. Matsumoto, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, R. Kita, Systematic study of BaSnO3 doped YBa2Cu3O7-x films, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2009.05.080, 469, 15-20, 1380-1383, 2009.08.
164. T. Ozaki, Y. Yoshida, Y. Ichino, T. Harada, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii, M. Mukaida, R. Kita, Surface morphology and microstructure of Sm1+xBa2-xCu3Oy thin films including self-organized columnar pinning centers, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2009.05.082, 469, 15-20, 1388-1391, 2009.08.
165. Y. Ichino, Y. Yoshida, S. Funaki, T. Ozaki, Y. Takai, K. Matsumoto, M. Mukaida, R. Kita, A. Ichinose, S. Horii, Reciprocal space mapping of BaZrO3 within (Nd,Eu,Gd)Ba2Cu3Oy films prepared by various film growth techniques, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2009.05.237, 469, 15-20, 1400-1403, 2009.08.
166. A. Ichinose, P. Mele, K. Matsumoto, H. Kai, M. Takamura, K. Yamada, M. Mukaida, S. Horii, S. Funaki, Y. Ichino, Y. Yoshida, R. Kita, Microstructures of REBa2Cu3Oy films containing artificial pinning centers of various dimensions, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2009.05.079, 469, 15-20, 1374-1379, 2009.08, To improve critical current density, J(c), under magnetic fields and at 77 K, some pinning centers have been introduced into REBa2Cu3Oy films (RE: rare earth elements). Pinning centers have been distinguished as one-dimensional, two-dimensional or three-dimensional artificial pinning centers (APCs) oil the basis of their structural dimension. One-dimensional and three-dimensional APCs have considerably improved J(c) as a result of our efforts. For example, BaZrO3 or BaSnO3 nanorods are significantly effective one-dimensional APCs. It is found that the nanorod structure can be controlled and the J(c)-B properties vary depending on the nanorod structure. Moreover, the principle of two-dimensional APCs, which have been successfully designed in a multilayer structure, has been clarified. In this paper, the microstructures of the one- and two-dimensional APCs, such as the nanorods and the boundaries, are described in particular. The J(c)-B properties also are discussed. (C) 2009 Elsevier B.V. All rights reserved..
167. T. Harada, Y. Yoshida, Y. Ichino, T. Ozaki, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii, M. Mukaida, R. Kita, Jc of Sm1+xBa2-xCu3Oy films improved in the whole angle range by introducing BaZrO3 nanoparticles, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2009.05.247, 469, 15-20, 1392-1395, 2009.08.
168. Hideki Kai, S. Horii, A. Ichinose, K. Yamada, R. Kita, M. Mukaida, R. Teranishi, N. Mori, Influence of Growth Temperature on Microstructure and Superconducting Properties of ErBa2Cu3O7-delta Films With Ba(Er0.5Nb0.5)O-3 Nanorods, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 10.1109/TASC.2009.2018811, 19, 3, 3435-3438, 2009.06, Influence of growth temperatures are discussed for microstructures and superconducting properties of ErBa2Cu3O7-delta films with Ba(Er0.5Nb0.5)O-3 nanorods grown by pulse laser deposition on SrTiO3 substrates. The nanorods were observed in transmission electron microscopy images of the films. Nanorods were thinner and denser at a lower growth temperature. The J(C) performance in magnetic fields relates closely the morphology of introduced nanorods with growth temperature..
169. Y. Yoshida, Y. Ichino, T. Ozaki, S. Funaki, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii, M. Mukaida, R. Kita, Improved flux pinning in nanostructured rebco films controlling the APC growth mechanism, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2009.2018737, 19, 3, 3262-3265, 2009.06.
170. N. Mori, K. Yoshida, Y. Miyanaga, K. Yamada, R. Teranishi, M. Mukaida, Growth process of Y123 crystal grains in the film fabricated by TFA-MOD method, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2009.05.026, 469, 15-20, 1341-1344, 2009.10, To clarify the growth mechanism of YBa2Cu3O7-X (Y123) crystals in the multi-coated film fabricated by the trifluoroacetates-metal organic deposition (TFA-MOD) method, the growth processes of Y123 crystal grains were studied by the experimental method and the numerical method. Microstructures of growing Y123 crystals were revealed through transmission electron microscopy (TEM) observations of the specimens quenched during the growth of Y123 crystals on LaAlO3 (LAO) substrates. It was observed that some a-axis grains grow among many c-axis grains, and they have some terraces near the initial boundaries of multi-coated layers. The above terraces of a-axis grains were considered to form by the change in c-axis (c-plane) growth rate of a-axis grains, which may have some dislocations and/or stacking faults. The growth processes and the above microstructures of faceted Y123 crystal grains were also shown by the two-dimensional numerical simulation using c- and a-axes growth rate functions. © 2009 Elsevier B.V. All rights reserved..
171. M. Mukaida, S. Yasunaga, R. Teranishi, N. Mori, A. Ichinose, S. Horii, K. Matsumoto, Y. Yoshida, R. Kita, Growth of BaSnO3 doped ErBa2Cu3O 7-δ Thin Films on MgO Substrates for High Jc Applications, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2009.2018418, 19, 3, 3416-3419, 2009.06.
172. S. Funaki, Y. Yoshida, Y. Ichino, T. Ozaki, T. Harada, Y. Takai, K. Matsumoto, A. Ichinose, M. Mukaida, R. Kita, S. Horii, Flux pinning properties and microstructure in Sm1+xBa 2-xCu3Oy films with BaZrO3 nanorods fabricated by vapor-liquid-solid growth technique, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2009.2019194, 19, 3, 3168-3171, 2009.06.
173. T. Sueyoshi, K. Yonekura, R. Kajita, T. Fujiyoshi, M. Mukaida, R. Teranishi, H. Kai, K. Matsumoto, Y. Yoshida, A. Ichinose, S. Horii, S. Awaji, K. Watanabe, Flux pinning properties of nano-rods comprised of BaMO3 (M = Zr, Sn) in REBa2Cu3O7-δ thin films prepared by PLD method, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2009.05.083, 469, 15-20, 1396-1399, 2009.08.
174. K. Matsumoto, P. Mele, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, R. Kita, Flux pinning characteristics of artificial pinning centers with different dimension, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2009.2018186, 19, 3, 3248-3253, 2009.06.
175. T. Ozaki, Y. Yoshida, Y. Ichino, T. Harada, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii, M. Mukaida, R. Kita, Flux pinning characteristics of Smi+xBa2-xCu 3Oy films with the additional c-axis correlated pinning centers, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2009.2018456, 19, 3, 3507-3510, 2009.06.
176. M. Sugimoto, R. Teranishi, S. Ooue, M. Mukaida, N. Mori, K. Yamada, H. Fukushima, T. Izumi, Y. Shiohara, Electrodeposition of textured nickel on nickel alloy Hastelloy, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2009.05.077, 469, 15-20, 1371-1373, 2009.10, We proposed a new method fabricating low-cost and mechanically strong tapes for coated conductors. In this method, Hastelloy® tape, which is a strong nickel alloy, is plated with a nickel film. A two-step plating was applied to obtain a textured nickel film. In the first step, a strike bath was used in order to plate a nickel film on Hastelloy surface. In the second step, the film was plated in a low cost watts bath. We controlled various plating conditions such as pH-condition, thickness, and current density in the watts bath to fabricate a textured nickel film. The crystal orientation of the nickel films was characterized by an X-ray diffraction method (XRD) with Cu Kα radiation. Preferred orientation of the film depends on pH of watts bath, nickel film thickness, and current density. The optimal conditions for obtaining a textured nickel film are pH of 4.5 for the watts bath, current density of 500 A/m2, and thickness of 92 μm. Finally, we succeeded in obtaining nickel films with 96% c-axis orientation. © 2009 Elsevier B.V. All rights reserved..
177. M. Takamura, M. Mukaida, S. Horii, A. Ichinose, R. Kita, M. Namba, S. Awaji, K. Watanabe, K. Matsumoto, Y. Yoshida, R. Teranishi, K. Yamada, N. Mori, Effects of the APC materials on c-axis correlated pinning effects in a-axis oriented Y123/2D APC multilayer films, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2009.05.225, 469, 15-20, 1545-1549, 2009.08, For a-axis oriented and c-axis in-plane aligned YBa(2)Cu(3)O(7-delta)/artificial pinning center (Y123/APC) alternately-layered thin films, effects of the APC materials on the multilayer structures are discussed. Pr123, (Y(1-x)Pr(x))123 and Gd(2)CuO(4)(Gd214) were used as APCs. The multilayer structure was observed for Y123/Pr123 films and Y123/Gd214 films. However, some grains are also grown in the Y123/Gd214 film. For the Y123/Pr123 multilayer film, each Pr123 layer act as two-dimensional APCs (2D APCs) in the magnetic field angular dependences of the critical current density. The growth mechanism of the multilayer structure in the Y123/2D APC films is discussed by a transmission electron microscopy and an atomic force microscope. It is found that two conditions are needed to obtain the c-axis correlated pinning effects by 2D APC in the a-axis oriented and c-axis in-plane aligned Y123/APC multilayer films: the same structure as Y123; Y-free APC materials. (C) 2009 Elsevier B.V. All rights reserved..
178. Y. Ichino, Y. Yoshida, K. Inoue, T. Ozaki, Y. Takai, K. Matsumoto, M. Mukaida, R. Kita, A. Ichinose, S. Horii, Effect of BaZrO3 addition and film growth on superconducting properties of (Nd, Eu, Gd)Ba2Cu3Oy thin films, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2009.2018207, 19, 3, 3144-3147, 2009.06.
179. Masafumi Namba, Satoshi Awaji, Kazuo Watanabe, Shun Ito, Eiji Aoyagi, Hideki Kai, Shuhei Yasunaga, Masashi Mukaida, Ryusuke Kita, Difference between BaSnO3 and BaZrO3 nano-rods for C-axis-correlated pinning properties in ReBa2Cu3O y, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2009.2018858, 19, 3, 3495-3498, 2009.06, In order to understand the vortex pinning properties by the BaZrO 3 (BZO) and BaSnO3 (BSO) nano-rods in Erl23 films, the microstructure and the angular dependence of Jc and resistivity were measured in detail for the BZO and the BSO added Er123 films with the similar matching field prepared by pulsed laser deposition. We found that the peak at B //c in the angular dependence of Jc for the Erl23 film with BSO nano-rods was higher in a wide magnetic field region up to the irreversible field than that for the Er123 film with BZO nano-rods, although the minimum values of the angular dependence of Jc are similar each other. Hence, the BSO nano-rods work more effectively as the c-axis-correlated pinning center than the BZO nano-rods because of the different elementary pinning energy of nano-rods. © 2009 IEEE..
180. R. Teranishi, A. Mitani, K. Yamada, N. Mori, M. Mukaida, M. Miura, K. Nakaoka, T. Izumi, Y. Shiohara, Dependence of microstructures on growth rate in YBCO films by TFA-MOD method, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2009.05.243, 469, 15-20, 1349-1352, 2009.10, YBa2Cu3Oy (YBCO) films grown by starting solutions with Ba-poor (Y:Ba:Cu = 1:1.5:3, Ba/Y = 1.5) have been reported to perform higher Jc than that for YBCO films with stoichiometric one due to smaller and less pores in YBCO films by metal organic deposition (MOD) using tri-fluoroacetates (TFA). However, we have reported that a lot of non-reacted particles such as Y and Cu oxides were remained for the YBCO film surface grown by the precursors using Ba-poor solution. In this study, influences of YBCO growth rate on microstructures of the YBCO film were discussed to control microstructures of these second phase particles. As a result, microstructures of the YBCO film depended strongly on the YBCO growth rate, residues of Y and Cu oxides were dispersed randomly throughout the YBCO film grown at higher growth rate. Consequently, it was succeeded to control the segregated phases as seen in the previous YBCO film with Ba/Y = 1.5 at the film surface into the YBCO film. Jc of the YBCO film grown at higher rate was a value almost equal to that grown at previous growth rate. © 2009 Elsevier B.V. All rights reserved..
181. Ryo Teranishi, K. Tada, J. Yoshida, K. Yamada, N. Mori, M. Mukaida, K. Nakaoka, M. Miura, M. Yoshizumi, T. Izumi, Y. Shiohara, Crystal growth of ba concentration controlled ybco films by tfa-mod process, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2009.2017958, 19, 3, 3200-3203, 2009.06, YBCO films grown by the starting solution with Ba-poor (cation ratio asY:Ba:Cu = l:1.5:3) have been reported to have higher Jc than that for YBCO films with stoichiometric composition due to smaller and less pores in TFA-MOD YBCO. In this study, Ba concentration in the Ba-poor YBCO films was controlled in film thickness direction, and influences of the Ba concentration gradient on microstructures and Jc properties were investigated to realize higher Jc. Precursor films with Ba-poor composition and with Ba-rich composition in the thickening direction were prepared and then the films were crystallized. Increasing the Ba concentration in thickening direction led to higher Jc than that of Ba-poor YBCO. Cross sectional TEM observations showed that the effective YBCO thickness increased for YBCO film with higher Ba concentration in comparison to the previous Ba-poor YBCO film © 2009 IEEE..
182. S. Funaki, Y. Yoshida, Y. Ichino, Y. Takai, A. Ichinose, K. Matsumoto, M. Mukaida, S. Horii, R. Kita, Crystal growth mechanism of VLS-Sm1+xBa2-xCu3Oy films including self-assembled BaZrO3 nanorods, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2009.05.048, 469, 15-20, 1414-1417, 2009.08.
183. M. Namba, S. Awaji, K. Watanabe, S. Ito, E. Aoyagi, H. Kai, M. Mukaida, R. Kita, Correlated pinning behavior in ErBa2Cu3Oy films with BaZrO3 nano-rods, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2009.05.046, 469, 15-20, 1404-1409, 2009.10, In REBa2Cu3Oy (RE123) films with BaZrO3 (BZO), the columnar shaped BZO precipitates, called nano-rods, are formed as the c-axis-correlated pinning centers. In order to understand the vortex pinning properties of RE123 films with BZO nano-rods, we measured the resistivity ρ and critical current density Jc of three different films, i.e. the Er123 films with 0, 1.5 and 3.5 wt% BZO prepared by pulsed laser deposition. We found that the peak related to the c-axis-correlated pinning in the angular dependence of Jc became large in a low field region but small in a high magnetic field with increasing BZO concentration. In addition, the irreversibility field at B||c-axis increased also with increasing BZO concentration, although the dip in the angular dependence of ρ and the peak of the Jc at B||c-axis decreased in the high magnetic field near the irreversible field. It is suggested that the BZO addition is effective to the enhancement of Jc in a low field region as well as the improvement of the irreversibility field. However, we have to consider the c-axis-correlated pinning by the edge dislocations as well as the nano-rods in order to understand it in a high field region. © 2009 Elsevier B.V. All rights reserved..
184. Masafumi Namba, Satoshi Awaji, Kazuo Watanabe, Hideki Kai, Masashi Mukaida, Satoru Okayasu, Correlated Pinning Behavior in ErBa2Cu3Oy Films with Columnar Defects, Applied Physics Express, 10.1143/APEX.2.113002, 2, 11, 2009.11, In this study c-axis-correlated pinning centers which are known to increase the critical current density (Jc) for B || c-axis were produced by heavy-ion-irradiation in REBa2Cu3Oy (RE: rare earth element RE123) coated conductors and the subsequent changes in J c were measured. A peak in the angular dependence of Jc induced by the defects was observed for applied magnetic fields of up to 13T for Er123 films with matching fields of Bφ = 0.1 and 1 T. We found that the columnar defects led to improvements in Jc even under applied magnetic fields more than 130 times higher than Bφ. © 2009 The Japan Society of Applied Physics..
185. Tomoya Horide, Kaname Matsumoto, Paolo Mele, Yutaka Yoshida, Ataru Ichinose, Ryusuke Kita, Shigeru Horii, Masashi Mukaida, Control of the glass-liquid transition temperature in YBa2 Cu3 O7-x films, Physical Review B - Condensed Matter and Materials Physics, 10.1103/PhysRevB.79.092504, 79, 9, 2009.03, Magnetic field dependences of the glass-liquid transition temperature (Tg) were studied in YBa2 Cu3 O7-x films containing various types of nanoinclusions. The vortex configuration (entangled or straight) and pinning strength for each vortex are crucial to the behaviors of Tg. c -axis correlated pinning centers optimize these factors and achieve the upper limit of Tg, which is determined by loss of line tension of vortices, if they are elongated through a thickness of a sample. By optimizing pinning centers, critical temperature, and a matching field, a Tg value of 77 K can be obtained in YBa2 Cu3 O7-x in a magnetic field as high as 27 T. © 2009 The American Physical Society..
186. Takatoshi Yoshimoto, G. Goto, M. Mukaida, R. Terasnishi, N. Mori, K. Yamada, S. Funaki, Y. Yoshida, A. Ichinose, K. Matsumoto, S. Horii, R. Kita, An attempt to arrange bzo nanorods into erbco thin films, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2009.2018759, 19, 3, 3420-3422, 2009.06, We arrayed BaZrO3 (BZO) nanorods as artificial pinning centers (APCs) into ErBa2Cu3O7-s (ErBCO) thin films to obtain a higher critical current density (Jc) in a magnetic field. In order to array BZO nanorods in ErBCO thin films, Zr nanoislands were put on (STO) substrates as seeds for BZO nanorod growth by using an electron beam lithography (EBL) process, a pulsed laser deposition (PLD) method and a lift off process. After that, we grew ErBCO thin films with BZO nanorods by the PLD method. The Zr nanoislands, arrayed on the STO substrates, were successfully observed by atomic force microscopy (AFM). The Zr nanoislands were 60∼70 nm in diameter and 2∼3 nm in height. Density of the Zr nanoislands was 27.7μm-2. Through structural analysis using X-ray diffraction and transmission electron microscopy (TEM) observation, it was confirmed that the ErBCO thin films had c-axis orientation with BZO nanorods. After oxygen annealing process, a critical temperature (Tc) of the film was 88.7 K. Jc measurement of the film in a magnetic field revealed that Jc deterioration was suppressed by introduction of the BZO nanorods. However, a Jc increase at the approximate maTching field was not confirmed at around calculated from density of the Zr nanoislands. © 2009 IEEE..
187. K. Yuki, M. Mukaida, H. Kai, R. Teranishi, K. Yamada, N. Mori, S. Horii, A. Ichinose, Y. Yoshida, K. Matsumoto, A research for improvement of crystallinity and critical temperature by oxygen pressure in ErBa2Cu3O7-δ films, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2009.05.081, 469, 15-20, 1384-1387, 2009.08.
188. H. Kai, S. Horii, A. Ichinose, R. Kita, K. Matsumoto, Y. Yoshida, T. Fujiyoshi, R. Teranishi, N. Mori, M. Mukaida, The effects of growth temperature on c-axis-correlated pinning centers in PLD-ErBa2Cu3O7-delta films with Ba(Er0.5Nb0.5)O-3, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 10.1088/0953-2048/23/2/025017, 23, 2, 025017, 2010.02, Effects of growth temperatures in epitaxial ErBa2Cu3O7-delta films with one-dimensional nanorods were discussed from their microstructures and superconducting properties. c-axis-oriented BaNb2O6-doped ErBa2Cu3O7-delta films were grown on (100)-oriented SrTiO3 substrates grown at 710 and 760 degrees C by pulsed-laser deposition. Atomic force microscopy analysis showed that film surface steps on the three-dimensional islands increased with decreasing growth temperature (T-S). Then, nanorod morphologies were also changed by T-S. Ba(Er0.5Nb0.5)O-3 nanorods were observed clearly in transmission electron microscopy images of the films. The nanorods were thinner and denser at a lower T-S under a nominal BaNb2O6 (BNO) doping concentration. In the case of T-S = 710 degrees C, the diameter and number density of nanorods with 1.5 wt% BNO doping were 4-6 nm and 2.6 x 10(11) cm(-2), respectively. Furthermore, the nanorods could effectively act as c-axis-correlated pinning centers in the film grown at a lower T-S. Consequently, the pinning effects were controlled by nanorod morphologies through varying the T-S..
189. S. Nagao, P. Mele, K. Matsumoto, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, R. Kita, Structural investigation of the BaSnO3-YBa2Cu3O7-x system, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2010.05.099, 470, 20, 1304-1307, 2010.11, We report the microstructure change of BaSnO3 (BSO)-YBa2Cu3O7, (YBCO) thin film system grown on SrTiO3 single crystal substrates by pulsed laser deposition with using the "surface-modified-target" and "mixture-target" methods. Although it was confirmed that the thick BSO nanorods incorporated to YBCO films act as strong artificial pinning centers, the formation mechanism of the nanorods is still unclear. The purpose of this work is to extend the structural investigation to higher contents of BSO (up to 71 vol.%) in order to enlighten the relationship among interfacial energy, morphology and pinning performance in binary BSO-YBCO films. (C) 2010 Elsevier B.V. All rights reserved..
190. K. Nakagawa, S. Nakayama, A. Saito, S. Ono, H. Kai, M. Mukaida, T. Honma, S. Ohshima, Relationship between intrinsic surface resistance and critical current density of YBCO thin films with various thickness, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2010.05.113, 470, 20, 1361-1364, 2010.11, We investigated the relationship between the intrinsic surface resistance (Rint s) and critical current density (Jc) of YBa2Cu3Oy (YBCO) film thinner than the penetration depth (kL). The measured YBCO films were deposited on CeO 2-buffered r-cut Al2O3 substrates by the pulsed laser deposition method. The thicknesses of these films were 300, 200, and 100 nm, respectively. The Rint s means the surface resistance of YBCO film removing the loss by the impedance of the substrates. The effective surface resistance (Rf) including the impedance of the substrate and the J c of each YBCO film were measured using the dielectric resonator method at 21.8 GHz and the inductive method. We calculated Rint s by using phenomenological expressions and the Reff s value. The Rint s values of each YBCO film were almost the same in the measured temperature region. As a result, we found that Rint s was in inverse proportion to the Jc of YBCO film thinner than λL. © 2010 Elsevier B.V. All rights reserved..
191. P. Mele, K. Matsumoto, Y. Haruyama, M. Mukaida, Y. Yoshida, Y. Ichino, T. Kiss, A. Ichinose, Pulsed laser deposition and in-field characterization of FeTe0.8S0.2 epitaxial thin films with enhanced superconducting properties, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2010.05.028, 470, 20, 1033-1037, 2010.11, Fe-Te-S thin films deposited by pulsed laser deposition at 400 degrees C on SrTiO3 (1 0 0) and MgO (1 0 0) single crystals showed epitaxy and 4-fold symmetry. Films deposited on both substrates reached zero resistance condition (T-c(0) = 3.54 K on STO and 5.37 K on MgO) and presented large upper critical field (B-c2(0) = 61.1 T on STO and 74.2 T for MgO using 90% of the normal state resistance and Werthamer-Helfand-Hohenberg model), indicating that the coherence length xi(0) of the present films is very short (xi(0) = 2.3 nm on STO and 2.1 nm on MgO). (C) 2010 Elsevier B.V. All rights reserved..
192. L. Miu, I. Ivan, P. Badica, G. Jakob, D. Miu, P. Mele, K. Matsumoto, M. Mukaida, Y. Yoshida, T. Horide, A. Ichinose, S. Horii, Origin of the fast magnetization relaxation at low temperatures in HTS with strong pinning, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2010.05.054, 470, 20, 1126-1129, 2010.11, The temperature T variation of the normalized magnetization relaxation rate S in high-temperature superconductors (HTS) with strong vortex pinning exhibits a maximum in the low-T range. This was reported for various HTS, and the origin of the faster relaxation at low T appearing in standard magnetization relaxation measurements was usually related to specific pinning properties of the investigated specimens. Since the observed behaviour seems to be characteristic to all HTS with enhanced pinning (generated by random and/or correlated disorder), we show that the S(T) maximum can be explained in terms of classic collective vortex creep. The influence of thermo-magnetic instabilities in the low-T range is also evidenced. The collective (elastic) creep regime is generated by the T dependent macroscopic currents induced in the sample during standard magnetization measurements. © 2010 Elsevier B.V. All rights reserved..
193. M. Takamura, M. Mukaida, S. Horii, A. Ichinose, R. Kita, K. Matsumoto, Y. Yoshida, M. Namba, S. Awaji, K. Watanabe, R. Teranishi, N. Mori, Matching field effects in c-axis in-plane aligned a-axis-oriented YBa2Cu3Oy films with two-dimensional artificial pinning centers induced by multilayered nano-structures, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 10.1088/0953-2048/23/4/045023, 23, 4, 2010.04, A relationship between microstructures of YBa2Cu3Oy (Y123) films with two-dimensional artificial pinning centers (2D APCs) and their critical current density (J(c)), especially under matching fields (B-phi), is discussed. Using a pulsed laser deposition (PLD) method, c-axis in-plane aligned a-axis-oriented Y123/Pr123 multilayer films were grown on substrates. The Pr123 interlayer distance was changed by controlling a target shape and its rotation speed in the PLD process. The multilayer structure was observed in cross-sectional transmission electron microscopy images. Critical temperatures of the films decrease as the Y123 layer becomes thinner. The magnetic field (B) dependence of J(c) showed that the interlayers act as 2D APCs in multilayer films. The matching effects were observed in two ways: J(c)(B parallel to c)/J(c)(B parallel to a)-B curves and irreversibility lines..
194. S. Horii, H. Kai, M. Mukaida, J. Shimoyama, K. Kishio, Irreversibility lines in ErBa2Cu3Oy thin films with Ba-Nb-O nanorods, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2009.11.046, 470, S1030-S1031, 2010.12, We report vortex-Bose-glass-like irreversibility lines (IL) depending on both growth temperature and nominal content of a nanorod material in Er-Ba-Cu-O films containing nanorods. The IL was expanded to higher magnetic fields with decreasing growth temperature (T-s), while T-c decreased. Our findings indicate that T-s in the production process of coated conductors containing nanorods is an important determination factor of critical current performance under high magnetic fields. (C) 2009 Elsevier B.V. All rights reserved..
195. N. Mori, T. Maebatake, R. Teranishi, K. Yamada, M. Mukaida, M. Miura, M. Yoshizumi, T. Izumi, In situ observation and simulation of growth process of faceted RE123 crystals, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2010.05.090, 470, 20, 1266-1270, 2010.11, To clarify the growth mechanism of faceted REBa2Cu 3O7 δ (RE123, RE = Sm, Y) crystals, the growth process of the crystals was observed in situ by using a high temperature microscope. The growth rate of each faceted interface of a crystal growing from the liquid + 211 phases under an undercooling was obtained from the relationship between the position of each interface and growth time. It was observed that some of the faceted interfaces of a growing crystal stopped growing after a period of time, while other interfaces continued to grow with a growth rate approximated by a function of the undercooling. The above stoppage of the growth was observed in situ for the first time, and this fact could give powerful support to the mechanism for a similar phenomenon in REBCO films which were fabricated by the trifluoroacetates metal organic deposition method: growing microstructures of RE123 crystals in the film were revealed by transmission electron microscopy (TEM) for quenched specimens. Some very thin a-axis grains were formed by a change in c-axis growth rate. Furthermore, we showed the above growth and stop phenomena of faceted interfaces of REBCO crystal grains using numerical simulations. © 2010 Elsevier B.V. All rights reserved..
196. T. Nakamura, R. Kita, S. Kawabata, O. Miura, A. Ichinose, K. Matsumoto, Y. Yoshida, M. Mukaida, S. Horii, INFLUENCE OF COATING SOLUTION COMPOSITION ON REBa2Cu3Oy (RE = Gd AND Sm, Eu, Gd) FILMS FABRICATED BY FLUORINE-FREE METAL-ORGANIC DEPOSITION, MODERN PHYSICS LETTERS B, 10.1142/S0217984910023189, 24, 12, 1165-1172, 2010.05, GdBa2Cu3Oy (GdBCO) and Sm0.33Eu0.33Gd0.33Gd0.33Ba2Cu3Oy (SEC) films were prepared by metal-organic depositon (MOD) using two fluorine-free solutions: a metal 2-ethylhexanate (2-EH) and a complex solution (CS) cosisting of metal 2-EH and metal-naphthenate. We investigated the effects of these new fluorine-free solutions, and their potential use in the fabrication of several REBCO (RE: rare earth) materials. The crystal growth, surface morphology, and supreconducting properties of films prepared on single-crystal LaAlO3 substrates at low oxygen partial presuure strongly depended stability of the superconduting phase during heat treatment. On the other hand, films prepared by CS had a flat superconducting matrix, with a roughness of several tens of nm and large precipitates 2-3 mu m in diameter. In addtion, the CS films had a higher critical temperature (91.2K) than the 2-EH film. The zero-field critical current density at 77.3 K was 0.19 MA/cm(2) for 2-EH films, and 0.61 MA/cm(2) for CS films..
197. A. Ichinose, H. Kai, M. Mukaida, S. Horii, R. Kita, K. Matsumoto, Y. Yoshida, Growth mechanism of nanorods in REBa2Cu3Oy films (RE: rare-earth element), JOURNAL OF CRYSTAL GROWTH, 10.1016/j.jcrysgro.2010.06.033, 312, 20, 2914-2918, 2010.10, Critical current density under magnetic fields has been improved by the introduction of artificial pinning centers. Nanorods in REBa2Cu3Oy films are significantly effective as c-axis-correlated pinning centers. However, nanorods sometimes tilt from the c-axis direction of superconducting films. To understand the mechanism of nanorod tilting. ErBa2Cu3Oy films containing Ba(Nb0.5Er0.5)O-3 (BNO) nanorods were deposited on a SrTiO3 single crystal with a vicinal surface. Microstructures of the nanorods were examined by transmission electron microscopy (TEM). As a result, it was found that BNO nanorods grew diagonally from steps of the substrate surface in cross-sectional TEM images. The mechanism of the diagonal growth of nanorods can be explained by the segregation coefficient. (C) 2010 Elsevier B.V. All rights reserved..
198. R. Teranishi, Y. Miyanaga, K. Yamada, N. Mori, M. Mukaida, M. Miura, M. Yoshizumi, T. Izumi, M. Namba, S. Awaji, K. Watanabe, Effects of tin-compounds addition on Jc and microstructure for YBCO films, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2010.05.085, 470, 20, 1246-1248, 2010.11, Tin-compounds were doped into YBa2Cu3O 7 δ (YBCO) films as pinning centers to enhance Jc in magnetic fields. YBCO films were grown by a metal organic deposition process using tri-fluoroacetates starting solutions. Tin-acetylacetonate salts were then dissolved into the starting solution as pinning centers. Jc of the YBCO films with tin-acetylacetonates were enhanced in all magnetic field angles. Transmission electron microscopy (TEM) and TEM-EDS (Energy Dispersive X-ray Spectroscopy) observations revealed the existence of tin-compound particles with the size of about 30 nm in the YBCO film. These nano particles were distributed randomly in the film and were considered to act as 3-dimentional pinning centers. © 2010 Elsevier B.V. All rights reserved..
199. T. Maebatake, N. Mori, R. Teranishi, M. Mukaida, K. Yamada, M. Miura, M. Yoshizumi, T. Izumi, Effects of joining conditions on the structures and properties of joints of REBCO coated conductors, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2010.05.112, 470, 20, 1358-1360, 2010.11, We investigated the joining of two REBCO (REBa2Cu 3O7 X, RE = Y, Gd) coated conductors using the diffusion joint process. REBCO coated conductors with stabilizing silver layer were joined by various joining conditions. Two pieces of the silver layer of tapes were overlapped in a face to face manner. Then, the pieces were pressurized and heat-treated at about 623-673 K under a pressure using some weights in oxygen atmosphere. Finally, the joint resistivity was obtained as low as about 10 nΩcm2 by 10 MPa for YBCO tape. The joint resistivity of the GdBCO tape was 50-60 nΩ cm2, which was higher than YBCO, but improved to 37 nΩ cm2 at 10 MPa by improving the joining conditions. Influences of joining conditions such as pressure and evenness of specimens and holders were investigated on joint adhesion and resistivity. © 2010 Published by Elsevier B.V..
200. S. Saini, M. Takamura, M. Mukaida, S. J. Kim, Microwave dependence of a-axis oriented YBa2Cu3O 7Thin film, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2010.2087310, 21, 3, 602-605, 2011.06, The a-axis oriented YBa2Cu3O7 thin films were grown on SrLaO4(100) substrate with a buffer layer of 50 nm thick Gd2CuO4 using pulsed laser deposition technique. The thickness of Y-123 thin film was about 500 nm. Intrinsic Josephson junctions (CuO2 planes) were aligned perpendicular to the substrate in the thin films. The bridge type pattern was fabricated using focused ion beam milling technique in such a way so that the current flow along the -axis in thin film. The dimensions of bridge were 1μ in length along the c-axis and 5μ in width along the b-axis. The resistance vs. temperature characteristics showed transition temperature of about 89 K. The critical current density(Jc) of 2 106A/cm2 was measured from current-voltage(I-V) characteristics at 10 K. The samples were irradiated with external microwave at 20 GHz and the was suppressed with increase in power. This suppression in indicates the formation of layered structure with strong coupling. The voltage steps were appeared with microwave irradiation in characteristics. The values of voltage steps were irregular and change with increase in power. We have also studied all a-axis oriented multilayered thin films of YBa2Cu3O7 (Y123) and PrBa2Cu3O7 (Pr123). We fabricated a submicron stack in which Josephson junctions were forming by Y123 and Pr123. The submicron stack showed response with microwave irradiation of different frequency and power. The transport characteristics of these thin films are discussed in detail. © 2010 IEEE..
201. T. Maebatake, Y. Ichinose, K. Yamada, N. Mori, R. Teranishi, M. Inoue, T. Kiss, M. Yoshizumi, T. Izumi, K. Kaneko, S. Munetoh, M. 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. © 2011 Elsevier B.V. All rights reserved..
202. K. Nakagawa, T. Honma, K. Takeda, S. Ono, H. Kai, A. Saito, M. Mukaida, K. Nakajima, S. Ohshima, Intrinsic surface resistance of ybco thin films under dc magnetic field, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2010.2086042, 21, 3, 587-590, 2011.06, We investigated the dc magnetic field and temperature dependences of the microwave intrinsic surface resistance (Rs int) of YBa 2Cu3Ooy (YBCO) superconducting thin films with various thicknesses. We used YBCO films from 100, 200, and 300 nm thick YBCO films deposited on CeO2/Al2O3 substrates. The (Rs int) is means the surface resistance of YBCO film without the dielectric loss of the substrates. The (Rs int) was obtained from measured surface resistance (Rs) by using a phenomenological equation. The (Rs) was measured using the dielectric resonator method at 21.8 GHz. A dc magnetic field of up to 5.0 T was applied parallel to the c-axis of the superconducting thin films during the (R s) measurements. The (Rs int) of the YBCO thin films increased when the dc magnetic field was applied. These relations could be explained with the two-fluid model for high-frequency and high-magnetic field limits. The (Rs int) ratio (defined as (Rs int) (5T)/ (Rs int) (OT) slightly decreased with the film thickness. These results indicate that the (Rs int) of HTS films depends on the film thickness in the dc magnetic field and the (Rs int) in a dc magnetic field may be related to the pinning center in the HTS films. © 2010 IEEE..
203. M. Haruta, T. Sueyoshi, T. Fujiyoshi, M. Mukaida, H. Kai, K. Matsumoto, P. Mele, T. Maeda, S. Horii, Growth temperature dependence of flux pinning properties in ErBa 2Cu3Oy thin films with nano-rods, Physica C: Superconductivity and its Applications, 10.1016/j.physc.2011.05.095, 471, 21-22, 944-946, 2011.11, Irreversibility lines and distributions of local critical current density (Jcl) based on the percolation transition model were affected by the growth temperature (Ts) in 3.5 wt.%-BaNb2O 6-doped ErBa2Cu3Oy thin films. The vortex-Bose-glass-like state appeared by the introduction of nano-rods, and this vortex state was affected by Ts. The shape and width of the J cl distribution strongly depended on Ts. These results are probably caused by variations of the density and the growth direction for nano-rods reflecting Ts. The growth temperature is an important factor to achieve higher critical current properties under magnetic fields for coated conductors of rare-earth-based cuprates with nano-rods. © 2011 Elsevier B.V. All rights reserved..
204. K. Yoshida, Y. Yoshida, Y. Ichino, Y. Takai, A. Ichinose, K. Matsumoto, T. Kiss, M. Mukaida, Epitaxial films of FeTe1-xSx fabricated by second harmonic Nd:YAG pulsed laser deposition, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2011.05.154, 471, 21-22, 1185-1188, 2011.11, Fe(Te,S) has a tetragonal PbO type structure with T-c(onset) of around 10K. which is the simplest structure among iron-based superconductors. We deposited Fe(Te,S) thin films by PLD method using the second harmonic light of Nd:YAG pulsed laser (wavelength = 532 nm) in the range of a deposition rate from 14 pm/s to 56 pm/s on MgO, SrTiO3 and LaAlO3 substrates. We obtained the thin films showed the c-axis orientation normal to the film surface and in-plane alignment. The film deposited on LaAlO3 showed T-c(onset) of 9.3 K. T-c(onset) and T-c(zero) increased to 11 K and 6.6 K respectively by the excess adding Te to the stoichiometric target. T-c(onset) was higher than that of a Fe(Te,S) bulk. The lattice constant of the films was strongly related to T-c(onset), T-c(onset) has local maximum value at 6.195 angstrom of c-axis length. (C) 2011 Published by Elsevier B.V..
205. S. Saini, M. Takamura, M. Mukaida, S. J. Kim, Electrical characterization of a-axis oriented Y123 thin film grown using pulsed laser deposition, Current Applied Physics, 10.1016/j.cap.2011.05.019, 11, 5, S79-S81, 2011.09, The thin film of a-axis oriented YBa2Cu3O7 (Y123) were grown on SrLaGaO4 (100) substrate with a buffer layer of 50 nm thick Gd2CuO4 using pulsed laser deposition technique. The thickness of Y123 thin film is about 400 nm CuO2 planes are aligned perpendicular to the substrate in the thin films. A micron-bridge was fabricated using focused ion beam milling technique in such a way that the current was forced to flow along the c-axis in thin film. Intrinsic Josephson junctions are aligned along the c-axis. The dimensions of bridge are 1 μm in length along the c-axis and 5 μm in width along the b-axis. Transition temperature (TcON) is about 84 K with single phase. The critical current density (Jc) of 2 × 106 A/cm 2 was measured from current-voltage (I-V) characteristics at 10 K. The samples were irradiated with external microwave of 20 GHz at different power and the Jc was suppressed as we increased the power. This suppression in Jc indicates the formation of layered structure with strong coupling. The voltage steps are appeared in non-linear I-V characteristics with microwave irradiation. The voltage steps are collective response of intrinsic Josephson junctions of micron-bridge. © 2011 Elsevier B.V. All rights reserved..
206. Satoshi Awaji, Masafumi Namba, Kazuo Watanabe, Shun Ito, Eiji Aoyagi, Hideki Kai, Masashi Mukaida, Satoru Okayasu, Cooperative behavior of the random and correlated pinning in Er123 films with columnar defects, IEEE Transactions on Applied Superconductivity, 10.1109/TASC.2010.2089588, 21, 3, 3192-3195, 2011.06, The flux pinning behaviors for the heavy ion irradiated Er123 films are investigated based on the detailed Jc(B,T,θ) properties. The double peaks of Fp curves for B // c appear in case of the matching field of 0.3 T along c-axis and 1.7 T tilted from c-axis. In addition, the peaks on Jc (θ) at θ = 0° (B // c) , which originate from the columnar defects, decrease with increasing magnetic field but increase again near the irreversibility field.We found that the cooperation model of the c-axis correlated and random pinning centers can describe the observed double peak behavior of Fp(B) and the angular dependence of Jc related to the correlated pinning. © 2010 IEEE..
207. S. Awaji, M. Namba, K. Watanabe, H. Kai, M. Mukaida, S. Okayasu, Flux pinning properties of correlated pinning at low temperatures in ErBCO films with inclined columnar defects, Journal of Applied Physics, 10.1063/1.3675181, 111, 1, 2012.01, The effect of c-axis correlated pinning on the critical current density at low temperatures under high magnetic fields was investigated on the basis of the transport critical current density and irreversibility field properties of an ErBa 2Cu 3Oy film with inclined columnar defects. We found that the contribution of correlated pinning on J c decreased drastically with decreasing temperature under high magnetic fields above the matching field, but still retained more than a 60% enhancement at 13 K. These effects of correlated pinning can be described using a cooperative model based on a combination of correlated and random pinning. At low temperatures, the presence of a matching field limited the flux pinning force for correlated pinning in comparison with that of random pinning, while the ratio of the maximum pinning force of the correlated pinning to the random one was proportional to the inverse of the irreversibility field. This suggests that the low efficiency of correlated pinning at low temperatures under a strong magnetic field is a result of a high irreversibility field and a low matching field. In order to improve the critical current properties at low temperatures under high magnetic fields, an increase in the matching field and/or the introduction of strong random pinning are effective. © 2012 American Institute of Physics..
208. Paolo Mele, Kaname Matsumoto, Kouhei Fujita, Yutaka Yoshida, Takanobu Kiss, Ataru Ichinose, Masashi Mukaida, Fe-Te-Se epitaxial thin films with enhanced superconducting properties, Superconductor Science and Technology, 10.1088/0953-2048/25/8/084021, 25, 8, 2012.08, Epitaxial Fe-Te-Se thin films were deposited by pulsed laser deposition at 250-600°C on SrTiO 3 (100), MgO (100), LaAlO 3 (100) and CaF 2 (100) single crystal substrates. The best superconducting film was grown on CaF 2: K and K with T dep=300°C and 3Hz. Critical current density J c (T=4.2K) was 0.41×10 6Acm 2 at 0T and 0.23×10 6Acm 2 at 9T. The angular dependence of J c shows a broad c-axis correlated peak when B3T. © 2012 IOP Publishing Ltd..
209. Sueyoshi, Tetsuro, Iwanaga, Yasuya, Fujiyoshi, Takanori, Takai, Yosuke, Muta, Mitsuhiro, Mukaida, Masashi, Ichinose, Ataru ,Ishikawa, Norito, Flux Pinning by Columnar Defects Along a-axis in a-axis Oriented YBCO Thin Films, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 10.1109/TASC.2019.2896473, 29, 5, 2019.08, Columnar defects (CDs) along a-axis were installed into an in-plane aligned a-axis-oriented YBa2Cu3Oy film by using heavy-ion irradiation, in order to clarify the influence of CDs on flux pinning properties around B parallel to ab. The critical current density J(c) atB parallel to c significantly decreases after the irradiation, since the CDs act as a channel for flux creep along their length. The magnetic field dependence of Jc at B parallel to ab, on the other hand, is weakened by the introduction of CDs. This means that the CDs can trap flux lines at B parallel to ab, whereas naturally growth defects working as effective ab-correlated PCs exist. The trapping angle of CDs along the a-axis is extremely narrow (similar to 5.8 degrees) in comparison with CDs along the c-axis and is roughly coincides with other ab-correlated PCs. The small trapping angle of CDs along the a-axis is attributed to strong line tension energy of flux lines with elliptical core around B parallel to ab..
210. T. Sueyoshi, Y. Iwanaga, T. Fujiyoshi, Yosuke Takai, Masashi Mukaida, M. Kudo, K. Yasuda, N. Ishikawa, Angular Behavior of Jc in GdBCO-Coated Conductors With Crossed Columnar Defects Around ab Plane, IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC, 10.1109/TASC.2016.2637338, 27, 4, 2017.06, We investigated in detail the flux pinning properties around B parallel to ab for GdBCO-coated conductors with crossed colum-nar defects produced by heavy-ion irradiation, where the crossing angle Theta(i) was systematically controlled in the range from +/- 5 degrees to +/- 15 degrees relative to the ab plane. A single peak of critical current den-sity J(c) centered at B parallel to ab occurs for the crossing angle of Theta(i) = +/- 5 degrees, where an upward shift in J(c) can be observed compared to an unirradiated sample. As the crossing angle is larger, the J(c) peak becomes smaller and broader while maintaining the peak at B parallel to ab. Increasing Theta(i) up to +/- 15 degrees, three J(c) peaks emerges at B parallel to ab and at the two irradiation angles, independently from the others. The crossover behavior from the single peak to the triple one around the ab plane is attributed to the strong line tension energy of flux lines around B parallel to ab, which derives from the elliptical nature of the core of flux lines in anisotropic superconductors..
211. Saini, Shrikant, Mele, Paolo, M. Mukaida, Kim, S. -J., Microwave irradiation on a-axis oriented Y123/Pr123 two-stacked Josephson junctions device, CURRENT APPLIED PHYSICS, 10.1016/j.cap.2015.01.021, 15, 5, 569-573, 2015.05, Two-stacked submicron Josephson junctions devices were fabricated in a-axis oriented YBaCu3O7 and PrBa2Cu3O7 (Y123/Pr123) multi layered thin films using focused ion beam milling technique. The transition temperature and critical current density (J(c)) of the device are about 83 K and 5 x 10(5) A/cm(2) at 20 K, respectively. The device was irradiated with external microwave of 10 GHz and studied at 20 K. The microwave induced voltage steps are observed in I-V characteristics. The supercurrent branch become resistive above a certain microwave power and also the Jc was suppressed as we increased the microwave power. Magnetic field modulation of critical current shows periodicity of about 2000 gauss correspond to the Josephson junctions in the stack..
212. Mele, P, Guzman, R, Gazquez, Jaume, Puig, Teresa, Obradors, Xavier, Saini, Shrikant, Yoshida, Yutaka, M. Mukaida, Ichinose, Ataru, Matsumoto, Kaname, Adam, Malik Idries, High pinning performance of YBa2Cu3O7-x films added with Y2O3 nanoparticulate defects, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 10.1088/0953-2048/28/2/024002, 28, 2, 024002, 2015.02.
213. B Maiorov, P Mele, S A Baily, M Weigand, S-Z Lin, F F Balakirev, K. Matsumoto, H Nagayoshi, S Fujita, Y Yoshida, Y Ichino, Takanobu Kiss, A. Ichinose, M. Mukaida, L Civale, Inversion of the upper critical field anisotropy in FeTeS films, Superconductor Science and Technology, doi:10.1088/0953-2048/27/4/044005, 27, 4, 2014 Supercond. Sci. Technol. 27 044005 doi:10.1088/0953-2048/27/4/044005, 2014.03.
214. Masashi Mukaida, Ichinose, Ataru, Mele, Paolo, Matsumoto, Kaname, Horii, Shigeru, Yoshida, Yutaka, An explanation for bends of 1-dimensional nanorods, Superconductivity Centennial Conference, DOI: 10.1016/j.phpro.2012.06.320, 36, 1631-1636, 2012.12, Growth of artificial pinning centers (APCs) in YBa2Cu3O7-delta (YBCO) films are discussed. The APCs used in this research are BaZrO3 and BaSnO3 nanorods which are reported by Mele et al. TEM images show these nanorods gradually bend accordingly with approaching to a surface of films. This feature showed a growth pattern like a firework. We explain the feature of the nanorods as follows; At an early growth stage, films grow in a layer by layer growth mode. The surface of the films is flat and very smooth. After the early growth stage, the film surface gradually becomes rough, indicating the film grows in a Stranski-Krastanov growth mode. This roughness was caused by a spiral growth of films with many steps. At the step of YBCO films, nanorod materials such as BaZrO3 are supplied from one direction. Then, the center of nanorods sifts to the same direction of the step flow. Then, the nanorods bend to the edge of the grains in the films. As a grain in spiral growth had a convex surface, nanorods bent to the direction perpendicular to the grain surface. Finally, nanorods in rough grains form firework structures..
215. Mele, Paolo, Matsumoto, Kaname, Fujita, Kouhei, Yoshida, Yutaka, Takanobu Kiss, Ichinose, Ataru, Masashi Mukaida, Fe-Te-Se epitaxial thin films with enhanced superconducting properties, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 10.1088/0953-2048/25/8/084021, 25, 8, 084021, 2012.08, Epitaxial Fe-Te-Se thin films were deposited by pulsed laser deposition at 250-600 degrees C on SrTiO3 (100), MgO (100), LaAlO3 (100) and CaF2 (100) single crystal substrates. The best superconducting film was grown on CaF2: T-c(onset) = 20.0 K and T-c(0) = 16.18 K with T-dep = 300 degrees C and 3 Hz. Critical current density J(c) (T = 4.2 K) was 0.41 x 10(6) A cm(-2) at 0 T and 0.23 x 10(6) A cm(-2) at 9 T. The angular dependence of J(c) shows a broad c-axis correlated peak when B >= 3 T. .
216. S. Awaji, M. Namba, K. Watanabe, H. Kai, M. Mukaida, S. Okayasu, Flux pinning properties of correlated pinning at low temperatures in ErBCO films with inclined columnar defects, J. Appl. Phys. , vol. 111 no. 1, p. 13914, 2012, 2012.01.
217. T. Maebatake, Y. Ichinose, K. Yamada, N. Mori, R. Teranishi, M. Inoue, T. Kiss, M. Yoshizumi, T. Izumi, K. Kaneko, S. Munetoh, M. Mukaida, Joint properties of REBCO coated conductors, Physica C , vol. 471 no. 21-22, p. 987-989, 2011, 2011.07.
218. Haruta, M, Sueyoshi, T, Fujiyoshi, T., Masashi Mukaida, Hideki Kai, Matsumoto, K, Mele, P, Maeda, T, Horii, S, Growth temperature dependence of flux pinning properties in ErBa2Cu3Oy thin films with nano-rods, Physica C , 10.1016/j.physc.2011.05.095, vol. 471 no. 21-22, p. 944-946, 2011, 2011.11.
219. S. Awaji, M. Namba, K. Watanabe, S. Ito, E. Aoyagi, H. Kai, M. Mukaida, S. Okayasu, Cooperative Behavior of the Random and Correlated Pinning in Er123 Films With Columnar Defects, IEEE Trans. Appl. Supercond. , vol. 21 no. 3, p. 3192-3195, 2011, 2011.07.
220. S. Saini, Makoto Takamura, Masashi Mukaida, S.-J. Kim, Microwave Dependence of a-Axis Oriented YBa2Cu3O7 Thin Film, IEEE Trans. Appl. Supercond. , 10.1016/j.cap.2011.05.019, vol. 21 no. 3, p. 602-605, 2011, 2011.07.
221. K. Nakagawa, T. Honma, K. Takeda, S. Ono, H. Kai, A. Saito, M. Mukaida, K. Nakajima, S. Ohshima, Intrinsic Surface Resistance of YBCO Thin Films Under DC Magnetic Field, IEEE Trans. Appl. Supercond. , vol. 21 no. 3, p. 587-590, 2011, 2011.07.
222. K. Yoshida, Y. Yoshida, Y. Ichino, Y. Takai, A. Ichinose, K. Matsumoto, T. Kiss, M. Mukaida, Epitaxial films of FeTe1-xSx fabricated by second harmonic Nd:YAG pulsed laser deposition, Physica C , vol. 471 no. 21-22, p. 132, 2011, 2011.07.
223. R. Teranishi, T. Tanaka, J. Matsuda, K. Nakaoka, T. Izumi, Y. Shiohara, N. Mori, M. Mukaida, Dependence of crystallization time on microstructures and Jc properties of YBa2Cu3Oy films by TFA-MOD chemical solution process, Mat. Sci. Eng. : B , vol. 173 no. 1-3, p. 61-65, 2010, 2010.10.
224. A. Ichinose, H. Kai, M. Mukaida, S. Horii, R. Kita, K. Matsumoto, Y. Yoshida, Growth mechanism of nanorods in REBa2Cu3Oy films (RE: rare-earth element), J. Cryst. Growth , vol. 312 no. 20, p. 2914-2918, 2010, 2010.10.
225. R. Teranishi, Y. Miyanaga, K. Yamada, N. Mori, M. Mukaida, M. Inoue, T. Kiss, M. Miura, M. Yoshizumi, T. Izumi, M. Namba, S. Awaji, K. Watanabe, Doping of Tin-oxides pinning centers into YBCO films by MOD method, J. Phys. : Conf. Ser. , vol. 234 no. 2, p. 22039, 2010, 2010.08.
226. Nobuyuki Mori, J Yoshida, T Maebatake, R Teranishi, M Mukaida, K Yamada, M Miura, M Yoshizumi, T Izumi, Effects of uniaxial constant pressures on the joint properties of REBCO coated conductors, J. Phys. : Conf. Ser. , vol. 234 no. 2, p. 22023, 2010, 2010.08.
227. M. Takamura, Sang-Jae Kim, A. Ichinose, M. Mukaida, R. Kita, R. Teranishi, N. Mori, K. Matsumoto, Y. Yoshida, Fabrication and characteristics of artificial SNS junctions using three axes orientation-controlled alpha-axis oriented Y123/Pr123 multilayer films, J. Phys. : Conf. Ser. , vol. 234 no. 1, p. 12044, 2010, 2010.08.
228. L. Miu, I. Ivan, P. Badica, G. Jakob, D. Miu, P. Mele, K. Matsumoto, M. Mukaida, Y. Yoshida, T. Horide, A. Ichinose, S. Horii, Magnetization relaxation in YBCO films with improved supercurrent transport properties, J. Phys. : Conf. Ser. , vol. 234 no. 1, p. 12026, 2010, 2010.08.
229. Hideki Kai, Ataru Ichinose, Shigeru Horii, Yutaka Yoshida, Ryusuke Kita, Kaname Matsumoto, Ryo Teranishi, Nobuyuki Mori, Masashi Mukaida, Relationship between surface structure and one-dimensional nanorod growth in ErBa2Cu3O7-d films on vicinal SrTiO3 substrates, J. Phys. : Conf. Ser. , vol. 234 no. 1, p. 12022, 2010, 2010.08.
230. K. Nakagawa, S. Nakayama, A. Saito, S. Ono, H. Kai, M. Mukaida, T. Honma, S. Ohshima, Relationship between intrinsic surface resistance and critical current density of YBCO thin films with various thickness, Physica C , vol. 470 no. 20, p. 1361-1364, 2010, 2010.07.
231. T. Maebatake, N. Mori, R. Teranishi, M. Mukaida, K. Yamada, M. Miura, M. Yoshizumi, T. Izumi, Effects of joining conditions on the structures and properties of joints of REBCO coated conductors, Physica C , vol. 470 no. 20, p. 1358-1360, 2010, 2010.07.
232. S. Nagao, P. Mele, K. Matsumoto, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, R. Kita, Structural investigation of the BaSnO3-YBa2Cu3O7-x system, Physica C , vol. 470 no. 20, p. 1304-1307, 2010, 2010.07.
233. N. Mori, T. Maebatake, R. Teranishi, K. Yamada, M. Mukaida, M. Miura, M. Yoshizumi, T. Izumi, In situ observation and simulation of growth process of faceted RE123 crystals, Physica C , vol. 470 no. 20, p. 1266-1270, 2010, 2010.07.
234. R. Teranishi, Y. Miyanaga, K. Yamada, N. Mori, M. Mukaida, M. Miura, M. Yoshizumi, T. Izumi, M. Namba, S. Awaji, K. Watanabe, Effects of tin-compounds addition on Jc and microstructure for YBCO films, Physica C , vol. 470 no. 20, p. 1246-1248, 2010, 2010.07.
235. L. Miu, I. Ivan, P. Badica, G. Jakob, D. Miu, P. Mele, K. Matsumoto, M. Mukaida, Y. Yoshida, T. Horide, A. Ichinose, S. Horii, Origin of the fast magnetization relaxation at low temperatures in HTS with strong pinning, Physica C , vol. 470 no. 20, p. 1153-1157, 2010, 2010.07.
236. L. Miu, I. Ivan, P. Badica, G. Jakob, D. Miu, P. Mele, K. Matsumoto, M. Mukaida, Y. Yoshida, T. Horide, A. Ichinose, S. Horii, Origin of the fast magnetization relaxation at low temperatures in HTS with strong pinning, Physica C , vol. 470 no. 20, p. 1126-1129, 2010, 2010.07.
237. T. Ozaki, Y. Yoshida, Y. Ichino, Y. Takai, A. Ichinose, K. Matsumoto, S. Horii, M. Mukaida, Y. Takano, Flux pinning properties and microstructure of SmBa2Cu3Oy thin films with systematically controlled BaZrO3 nanorods, J. Appl. Phys. , vol. 108 no. 9, p. 93905, 2010, 2010.06.
238. T. Nakamura, R. Kita, S. Kawabata, O. Miura, A. Ichinose, K. Mastumoto, Y. Yoshica, M. Mukaida, S. Horii, Influence of coating solution composition on REBa2Cu3Oy (RE = Gd and Sm, Eu, Gd) films fabricated by fluorine-free metal-organic deposition, Mod. Phys. Lett. B , vol. 24 no. 12, p. 1165-1172, 2010, 2010.06.
239. M. Takamura, M. Mukaida, S. Horii, A. Ichinose, R. Kita, K. Matsumoto, Y. Yoshida, M. Namba, S. Awaji, K. Watanabe, R. Teranishi, N. Mori, Matching field effects in c-axis in-plane aligned a-axis-oriented YBa2Cu3Oy films with two-dimensional artificial pinning centers induced by multilayered nano-structures, Supercond. Sci. Technol. , vol. 23 no. 4, p. 45023, 2010, 2010.06.
240. H. Kai, S. Horii, A. Ichinose, R. Kita, K. Matsumoto, Y. Yoshida, T. Fujiyoshi, R. Teranishi, N. Mori, M. Mukaida, The effects of growth temperature on c-axis-correlated pinning centers in PLD-ErBa2Cu3O7-d films with Ba(Er0.5Nb0.5)O3, Supercond. Sci. Technol. , vol. 23 no. 2, p. 25017, 2010, 2010.06.
241. T. Yoshimoto, Y. Ichino, Y. Yoshida, T. Kiss, M. Inoue, K. Matsumoto, A. Ichinose, H. Kai, R. Teranishi, N. Mori, M. Mukaida, A trial of Fe(Se1-xTex) thin film fabrication by pulsed laser deposition using ArF excimer laser, J. Phys. : Conf. Ser. , vol. 234 no. 1, p. 12051, 2010, 2010.06.
242. P. Mele, K. Matsumoto, Y. Haruyama, M. Mukaida, Y. Yoshida, Y. Ichino, T. Kiss, A. Ichinose, Pulsed laser deposition and in-field characterization of FeTe0.8S0.2 epitaxial thin films with enhanced superconducting properties, Physica C , vol. 470 no. 19, p. 1033-1037, 2010, 2010.06.
243. Paolo Mele, K. Matsumoto, Y. Haruyama, M. Mukaida, Y. Yoshida, Y. Ichino, T. Kiss, A. Ichinose, In-field characterization of FeTe0.8S0.2 epitaxial thin films with enhanced superconducting properties, Supercond. Sci. Technol. , vol. 23 no. 5, p. 52001, 2010, 2010.06.
244. Masafumi Namba, Satoshi Awaji, Kazuo Watanabe, Hideki Kai, Masashi Mukaida, and Satoru Okayasu, Correlated Pinning Behavior in ErBa2Cu3Oy Films with Columnar Defects, Appl. Phys. Exp., vol. 2 no. 7, p. 113002, 2009.11.
245. M. Takamura, M. Mukaida, S. Horii, A. Ichinose, R. Kita, M. Namba, S. Awaji, K. Watanabe, K. Matsumoto, Y. Yoshida, R. Teranishi, K. Yamada and N. Mori, Effects of the APC materials on c-axis correlated pinning effects in a-axis oriented Y123/2D APC multilayer films , Physica C: SuperconductivityVolume 469, , vol. 469, p. 1545-1549, 2009.10.
246. K. Yamada, M. Mitsuhara, S. Hata, Y. Miyanaga, R. Teranishi, N. Mori, M. Mukaida and K. Kaneko, Three-dimensional observation of microstructures in Y123 films fabricated by TFA-MOD method , Physica C: SuperconductivityVolume 469, , vol. 469, p. 1446-1449, 2009.10.
247. Y. Miyanaga, R. Teranishi, K. Yamada, N. Mori, M. Mukaida, T. Kiss, M. Inoue, K. Nakaoka, M. Yoshizumi, T. Izumi, Y. Shiohara, M. Nanba, S. Awaji and K. Watanabe, Effects of Sn-doping on JC?B properties and crystalline structure for YBCO films by advanced TFA-MOD method, Physica C: SuperconductivityVolume 469, , vol. 469, p. 1418-1421, 2009.10.
248. S. Funaki, Y. Yoshida, Y. Ichino, Y. Takai, A. Ichinose, K. Matsumoto, M. Mukaida, S. Horii and R. Kita, Crystal growth mechanism of VLS-Sm1+xBa2?xCu3Oy films including self-assembled BaZrO3 nanorods , Physica C: SuperconductivityVolume 469, , vol. 469, p. 1414-1417, 2009.10.
249. M. Namba, S. Awaji, K. Watanabe, S. Ito, E. Aoyagi, H. Kai, M. Mukaida and R. Kita, Correlated pinning behavior in ErBa2Cu3Oy films with BaZrO3 nano-rods, Physica C: SuperconductivityVolume 469, , vol. 469, p. 1404-1409, 2009.10.
250. Y. Ichino, Y. Yoshida, S. Funaki, T. Ozaki, Y. Takai, K. Matsumoto, M. Mukaida, R. Kita, A. Ichinose and S. Horii, Reciprocal space mapping of BaZrO3 within (Nd, Eu, Gd)Ba2Cu3Oy films prepared by various film growth techniques , Physica C: SuperconductivityVolume 469, , vol. 469, p. 1400-1403, 2009.10.
251. T. Sueyoshi, K. Yonekura, R. Kajita, T. Fujiyoshi, M. Mukaida, R. Teranishi, H. Kai, K. Matsumoto, Y. Yoshida, A. Ichinose, S. Horii, S. Awaji and K. Watanabe, Flux pinning properties of nano-rods comprised of BaMO3 (M = Zr, Sn) in REBa2Cu3O7?δ thin films prepared by PLD method, Physica C: SuperconductivityVolume 469, , vol. 469, p. 1396-1399, 2009.10.
252. T. Harada, Y. Yoshida, Y. Ichino, T. Ozaki, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii, M. Mukaida and R. Kita, Jc of Sm1+xBa2?xCu3Oy films improved in the whole angle range by introducing BaZrO3 nanoparticles , Physica C: SuperconductivityVolume 469, , vol. 469, p. 1392-1395, 2009.10.
253. T. Ozaki, Y. Yoshida, Y. Ichino, T. Harada, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii, M. Mukaida and R. Kita, Surface morphology and microstructure of Sm1+xBa2?xCu3Oy thin films including self-organized columnar pinning centers , Physica C: SuperconductivityVolume 469, , vol. 469, p. 1388-1391, 2009.10.
254. K. Yuki, M. Mukaida, H. Kai, R. Teranishi, K. Yamada, N. Mori, S. Horii, A. Ichinose, Y. Yoshida and K. Matsumoto, A research for improvement of crystallinity and critical temperature by oxygen pressure in ErBa2Cu3O7?δ films, Physica C: SuperconductivityVolume 469, , vol. 469, p. 1384-1387, 2009.10.
255. P. Mele, K. Matsumoto, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii and R. Kita, Systematic study of BaSnO3 doped YBa2Cu3O7?x films , Physica C: SuperconductivityVolume 469, , vol. 469, p. 1380-1383, 2009.10.
256. A. Ichinose, P. Mele, K. Matsumoto, H. Kai, M. Takamura, K. Yamada, M. Mukaida, S. Horii, S. Funaki, Y. Ichino, Y. Yoshida and R. Kita, Microstructures of REBa2Cu3Oy films containing artificial pinning centers of various dimensions, Physica C: SuperconductivityVolume 469, , vol. 469, p. 1374-1379, 2009.10.
257. M. Sugimoto, R. Teranishi, S. Ooue, M. Mukaida, N. Mori, K. Yamada, H. Fukushima, T. Izumi and Y. Shiohara, Electrodeposition of textured nickel on nickel alloy Hastelloy, Physica C: SuperconductivityVolume 469, , vol. 469, p. 1371-1373, 2009.10.
258. K. Kawabata, T. Nakamura, R. Kita, O. Miura, A. Ichinose, K. Matsumoto, Y. Yoshida, M. Mukaida and S. Horii, Fabrication and characterization of (Nd, Eu, Gd)Ba2Cu3Oy films by metal-organic deposition using TFA-containing solutions without introduction of water vapor , Physica C: SuperconductivityVolume 469, , vol. 469, p. 1353-1356, 2009.10.
259. R. Teranishi, A. Mitani, K. Yamada, N. Mori, M. Mukaida, M. Miura, K. Nakaoka, T. Izumi and Y. Shiohara, Dependence of microstructures on growth rate in YBCO films by TFA-MOD method , Physica C: SuperconductivityVolume 469, , vol. 469, p. 1349-1352, 2009.10.
260. R. Teranishi, K. Tada, J. Yoshida, K. Yamada, N. Mori, M. Mukaida, M. Inoue, T. Kiss, K. Nakaoka, M. Miura, M. Yoshizumi, T. Izumi and Y. Shiohara, High-Jc YBCO films using precursors with barium concentration gradient in film thickness by TFA-MOD process , Physica C: SuperconductivityVolume 469, , vol. 469, p. 1345-1348, 2009.10.
261. N. Mori, K. Yoshida, Y. Miyanaga, K. Yamada, R. Teranishi and M. Mukaida, Growth process of Y123 crystal grains in the film fabricated by TFA?MOD method , Physica C: SuperconductivityVolume 469, , vol. 469, p. 1341-1344, 2009.10.
262. R. Teranishi, J. Yoshida, N. Mori, K. Yamada, M. Mukaida, T. Kiss, M. Inoue, J. Matsuda, K. Nakaoka, T. Izumi and Y. Shiohara, JC properties and microstructures of YBCO films fabricated by low temperature calcination in TFA-MOD method , Physica C: SuperconductivityVolume 469, , vol. 469, p. 1332-1335, 2009.10.
263. R. Kita, N. Hosoya, N. Otawa, S. Kawabata, T. Nakamura, O. Miura, M. Mukaida, K. Yamada, A. Ichinose, K. Matsumoto, S. Horii and Y. Yoshida, Effects of RE2O3 (RE = Tm, Sc, Yb) addition on the superconducting properties of ErBa2Cu3Oy, Physica C: SuperconductivityVolume 469, , vol. 469, p. 1157-1160, 2009.10.
264. Toshinori Ozaki, Yutaka Yoshida, Yusuke Ichino, Takahiro Harada, Yoshiaki Takai, Kaname Matsumoto, Ataru Ichinose, Shigeru Horii, Masashi Mukaida, and Ryusuke Kita, Flux Pinning Characteristics of Sm1+xBa2-xCu3Oy Films With the Additional c-Axis Correlated Pinning Centers, IEEE Transactions on Applied Superconductivity, , vol. 19, p. 3507 - 3510, 2009.06.
265. Masafumi Namba, Satoshi Awaji, Kazuo Watanabe, Shun Ito, Eiji Aoyagi, Hideki Kai, Shuhei Yasunaga, Masashi Mukaida, and Ryusuke Kita , Difference Between BaSnO3 and BaZrO3 Nano-Rods for c-Axis-Correlated Pinning Properties in REBa2Cu3Oy, IEEE Transactions on Applied Superconductivity, , vol. 19, p. 3495 - 3498, 2009.06.
266. Hideki Kai, S.Horii, A.Ichinose, K.Yamada, R.Kita, M.Mukaida, R.Teranishi, and N.Mori, Influence of Growth Temperature on Microstructure and Superconducting Properties of ErBa2Cu3O7-δ Films With Ba(Er0.5Nb0.5)O3 Nanorods, IEEE Transactions on Applied Superconductivity, , vol. 19, p. 3435 - 3438, 2009.06.
267. Takatoshi Yoshimoto, G.Goto, M.Mukaida, R.Terasnishi, N.Mori, K.Yamada, S.Funaki, Y.Yoshida, A.Ichinose, K.Matsumoto, S.Horii, and R.Kita, An Attempt to Arrange BZO Nanorods Into ErBCO Thin Films, IEEE Transactions on Applied Superconductivity, , vol. 19, p. 3420 - 3422, 2009.06.
268. Masashi Mukaida, Shuhei Yasunaga, Ryo Teranishi, Nobuyuki Mori, Ataru Ichinose, Shigeru Horii, Kaname Matsumoto, Yutaka Yoshida, and Ryusuke Kita, Growth of BaSnO3 Doped ErBa2Cu3O7-δ Thin Films on MgO Substrates for High JC Applications, IEEE Transactions on Applied Superconductivity, , vol. 19, p. 3416 - 3419, 2009.06.
269. Yutaka Yoshida, Yusuke Ichino, Toshinori Ozaki, Shuhei Funaki, Yoshiaki Takai, Kaname Matsumoto, Ataru Ichinose, Shigeru Horii, Masashi Mukaida, and Ryusuke Kita, Improved Flux Pinning in Nanostructured REBCO Films Controlling the APC Growth Mechanism, IEEE Transactions on Applied Superconductivity, , vol. 19, p. 3262 - 3265, 2009.06.
270. Kaname Matsumoto, Paolo Mele, Ataru Ichinose, Masashi Mukaida, Yutaka Yoshida, Shigeru Horii, and Ryusuke Kita, Flux Pinning Characteristics of Artificial Pinning Centers With Different Dimension, IEEE Transactions on Applied Superconductivity, , vol. 19, p. 3248 - 3253, 2009.06.
271. R. Teranishi, K.Tada, J.Yoshida, K.Yamada, N.Mori, M.Mukaida, K.Nakaoka, M.Miura, M.Yoshizumi, T.Izumi, and Y.Shiohara, Crystal Growth of Ba Concentration Controlled YBCO Films by TFA-MOD Process, IEEE Transactions on Applied Superconductivity, , vol. 19, p. 3200 - 3203, 2009.06.
272. Shuhei Funaki, Yutaka Yoshida, Yusuke Ichino, Toshinori Ozaki, Takahiro Harada, Yoshiaki Takai, Kaname Matsumoto, Ataru Ichinose, Masashi Mukaida, Ryusuke Kita, and Shigeru Horii, Flux Pinning Properties and Microstructure in Sm1+xBa2-xCu3Oy Films With BaZrO3 Nanorods Fabricated by Vapor-Liquid-Solid Growth Technique, IEEE Transactions on Applied Superconductivity, , vol. 19, p. 3168 - 3171, 2009.06.
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277. P Mele, K Matsumoto, T Horide, A Ichinose, M Mukaida, Y Yoshida, S Horii and R Kita, Incorporation of double artificial pinning centers in YBa2Cu3O7?d films, Supercond. Sci. Technol., 21No1 015019, 2008.01.
278. Y. Tanaka, M. Mukaida, R. Teranishi, K. Yamada, A. Ichinose, K. Matsumoto, S. Horii, Y. Yoshida, R. Kita, T. Fujiyoshi, N. Mori, Fabrication and characterization of BaSnO3-doped NdBa2Cu3O7-d thin film, Physica C, 468, 1864-1868, 2008.01.
279. K. Yuki, H. Kai, M. Mukaida, S. Horii, R. Kita, A. Ichinose, Y. Yoshida, K. Matsumoto, R. Teranishi, K. Yamada, N. Mori, A research for controlling nanorod diameter in BaNb2O6 doped REBa2Cu3O7?δ films, Physica C, 468, 1861-1863, 2008.01.
280. S. Yasunaga, M. Mukaida, A. Ichinose, S. Horii, R. Teranishi, K. Yamada, K. Matsumoto, R. Kita, Y. Yoshida, N. Mori, Growth of BaSnO3 doped ErBa2Cu3O7?δ thin films for high Jc applications, Physica C, 468, 1858-1860, 2008.01.
281. H. Kai, M. Mukaida, R. Teranishi, N. Mori, K. Yamada, S. Horii, A. Ichinose, R. Kita, K. Matsumoto, Y. Yoshida, S. Awaji, K. Watanabe, M. Namba, T. Fujiyoshi, Effects of growth temperature for superconducting properties and microstructures of PLD-ErBa2Cu3O7?δ film with BaNb2O6, Physica C, 468, 1854-1857, 2008.01.
282. M. Takamura, M. Mukaida, S. Horii, A. Ichinose, R. Kita, S. Kato, K. Matsumoto, Y. Yoshida, K. Watanabe, S. Awaji, M. Namba, T. Fujiyoshi, R. Teranishi, K. Yamada, N. Mori, Electrical transport properties of Y123 films with 2-D apcs, Physica C, 468, 1851-1853, 2008.01.
283. S. Horii, T. Horide, K. Matsumoto, T. Ozaki, Y. Ichino, M. Mukaida, Y. Yoshida, A. Ichinose, J. Shimoyama, K. Kishio, Critical current properties at low angle grain boundaries in ErBa2Cu3Oy films, Physica C, 468, 1670-1673, 2008.01.
284. K. Yamada, A. Ichinose, S. Horii, H. Kai, R. Teranishi, M. Mukaida, R. Kita, S. Kato, Y. Yoshida, K. Matsumoto, S. Toh, Characterization of nanorods in BaNb2O6-doped Er123 films revealed by cross-sectional transmission electron microscopy, Physica C, 468, 1638-1642, 2008.01.
285. T. Fujiyoshi, M. Haruta, T. Sueyoshi, K. Yonekura, M. Watanabe, M. Mukaida, R. Teranishi, K. Matsumoto, Y. Yoshida, A. Ichinose, S. Horii, S. Awaji, K. Watanabe, Flux pinning properties of REBa2Cu3Oy thin films with BaZrO3 nano-rods, Physica C, 468, 1635-1637, 2008.01.
286. P. Mele, K. Matsumoto, T. Horide, A. Ichinose, M. Mukaida, Y. Yoshida, S. Horii, R. Kita, Incorporation of double artificial pinning centers in YBa2Cu3O7?δ films, Physica C, 468, 1631-1634, 2008.01.
287. A. Ichinose, P. Mele, T. Horide, K. Matsumoto, G. Goto, M. Mukaida, R. Kita, Y. Yoshida, S. Horii, Microstructures of REBa2Cu3Oy adding BaZrO3 or BaSnO3, Physica C, 468, 1627-1630, 2008.01.
288. Y. Ichino, Y. Yoshida, K. Inoue, S. Funaki, Y. Takai, K. Matsumoto, M. Mukaida, A. Ichinose, S. Horii, Enhancement of critical temperature of LaBa2Cu3Oy thin films by novel film growth technique, Physica C, 468, 1623-1626, 2008.01.
289. T. Ozaki, Y. Yoshida, Y. Ichino, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii, M. Mukaida, Flux pinning properties of Sm1+xBa2?xCu3Oy films with BaZrO3 nanorods fabricated by low-temperature growth technique, Physica C, 468, 1615-1618, 2008.01.
290. K. Inoue, Y. Yoshida, Y. Ichino, Y. Takai, K. Matsumoto, A. Ichinose, M. Mukaida, S. Horii, Superconducting properties in magnetic field of (Nd, Eu, Gd)1+xBa2?xCu3Oy thin films prepared by low temperature growth technique, Physica C, 468, 1611-1614, 2008.01.
291. Y. Yoshida, T. Ozaki, Y. Ichino, Y. Takai, K. Matsumoto, A. Ichinose, M. Mukaida, S. Horii, Progress in development of advanced PLD process for high Jc REBCO film, Physica C, 468, 1606-1610, 2008.01.
292. S. Funaki, Y. Ichino, Y. Yoshida, K. Inoue, Y. Takai, K. Matsumoto, M. Mukaida, A. Ichinose, S. Horii, Critical temperature of LaBa2Cu3Oy thin films by vapor?liquid?solid growth technique improved by the composition ratio in liquid phase, Physica C, 468, 1575-1578, 2008.01.
293. K. Tada, J. Yoshida, N. Mori, K. Yamada, R. Teranishi, M. Mukaida, T. Kiss, M. Inoue, Y. Shiohara, T. Izumi, J. Matsuda, K. Nakaoka, Growth process of Ba-poor YBCO film fabricated by TFA-MOD process, Physica C, 468, 1554-1558, 2008.01.
294. J. Yoshida, K. Tada, T. Tanaka, N. Mori, K.Yamada, R.Teranishi, M. Mukaida, T. Kiss, M. Inoue, Y. Shiohara, T. Izumi, K. Nakaoka, J. Matsuda, Effect of calcination conditions on microstructures and Jc of YBCO films fabricated by TFA-MOD method, Physica C, 468, 1550-1553, 2008.01.
295. A.Mitani, R.Teranishi, K.Yamada, N.Mori, M.Mukaida, T.Kiss, M.Inoue, Y.Shiohara, T.Izumi, K.Nakaoka, J.Matsuda, Effect of fabrication conditions on crystalline of SmBCO films fabricated by TFA-MOD method, Physica C, 468, 1546-1549, 2008.01.
296. T. Nakamura, R. Kita, O. Miura, A. Ichinose, K. Matsumoto, Y. Yoshida, M. Mukaida, S. Horii, Superconducting properties of GdBa2Cu3Oy films by metal?organic deposition using new fluorine-free complex solutions, Physica C, 468, 1542-1545, 2008.01.
297. N. Mori, K. Tada, K. Yamada, R. Teranishi, M. Mukaida, Numerical study on crystal growth process in YBCO film fabricated by TFA-MOD method, Physica C, 468, 1537-1541, 2008.01.
298. R. Teranishi, S. Yasunaga, H. Kai, K. Yamada, M. Mukaida, N. Mori, T. Fujiyoshi, A. Ichinose, S. Horii, K. Matsumoto, Y. Yoshida, R. Kita, S. Awaji, Superconducting properties of ErBCO films with BaMO3 nanorods (M = Zr and Sn) by pulsed laser deposition, Physica C, 468, 1522-1526, 2008.01.
299. R. Kita, S. Kato, T. Nakamura, O. Miura, R. Teranishi, S. Yasunaga, H. Kai, M. Mukaida, A. Ichinose, K. Matsumoto, M.S. Horii, Y. Yoshida, Stability of barium oxides in REBa2Cu3Oy superconductors, Physica C, 468, 1391-1394, 2008.01.
300. T. Horide, K. Matsumoto, Y. Yoshida, M. Mukaida, A. Ichinose, S. Horii, Tilt angle dependences of vortex structure and critical current density at low-angle grain boundaries in YBa2Cu3O7-x, Phys. Rev. B, vol.77no.13, 132502, 2008.01.
301. Kazuhiro Yamada, Ataru Ichinose, Shuhei Yasunaga, Ryo Teranishi, Masashi Mukaida, Shigeru Horii, Ryusuke Kita, Shingo Kato, Yutaka Yoshida, Kaname Matsumoto, and Shoichi Toh , Transmission Electron Microscopy Analysis of Nanorods in BaSnO3-Doped ErBa2Cu3O7-δ Films , Japanese Journal of Applied Physics, 47, 899-903, 2008.01.
302. Nobuyuki Mori, Ryo Teranishi, Keisuke Tada, Jiro Yoshida, Kazuhiro Yamada, and Masashi Mukaida , Formation of Microstructures and Continuous Heating and Time?Temperature Transformation Diagrams of YBa2Cu3O7-x Film Fabricated by Metal Organic Deposition with Trifluoroacetates , Japanese Journal of Applied Physics, 47, 7131-7135, 2008.01.
303. H Nasu, Y Yamada, M Mukaida and S Kubo, Liquid phase epitaxy of YBa2Cu3O7-δ film on single crystalline MgO and NdGaO3 substrate, J. Phys.: Conf. Ser., 97, 012274, 2008.01.
304. H Kai, M Mukaida, R Teranishi, N Mori, K Yamada, S Horii, A Ichinose, K Matsumoto, Y Yoshida, R Kita, S Kato, S Awaji, K Watanabe, M Namba and T Fujiyoshi, Superconducting properties and microstructure of PLD-ErBa2Cu3O7-δ films with BaNb2O6, J. Phys.: Conf. Ser., 97, 012143, 2008.01.
305. N Mori, M Mukaida, R Teranishi, K Yamada, T Tanaka and K Tada, Crystal growth process of Y123 film fabricated by modified TFA-MOD process, J. Phys.: Conf. Ser., 97, 012061, 2008.01.
306. Y Yoshida, T Ozaki, Y Takai, K Matsumoto, A Ichinose, S Horii, M Mukaida and Y Ichino, Progress towards nanostructured SmBCO film for controlling pinning properties, J. Phys.: Conf. Ser., 97, 012021, 2008.01.
307. S. Horii, H. Kai, M. Mukaida, K. Yamada, R. Teranishi, A. Ichinose, K. Matsumoto, Y. Yoshida, R. Kita, J. Shimoyama, K. Kishio, Vortex Bose glass in ErBa2Cu3Oy films with size-controlled nanorods, Appl. Phys. Lett., vol.93, no.15, 152506, 2008.01.
308. T. Horide, K. Matsumoto, P. Mele, A. Ichinose, R. Kita, M. Mukaida, Y. Yoshida, S. Horii , The crossover from the vortex glass to the Bose glass in nanostructured YBa2Cu3O7-x films , Appl. Phys. Lett., vol.92, no.18, 182511, 2008.01.
309. S. Horii, M. Takamura, M. Mukaida, A. Ichinose, K. Yamada, R. Teranishi, K. Matsumoto, R. Kita, Y. Yoshida, J. Shimoyama, K. Kishio , Two-Dimensional Vortex-Pinning Phenomena in YBa2Cu3Oy Films, Appl. Phys. Lett., vol.92, no.13, 132502, 2008.01.
310. K. Yamada, M. Mukaida, H. Kai, R. Teranishi, A. Ichinose, R. Kita, S. Kato, S. Horii, Y. Yoshida, K. Matsumoto, S. Toh, Transmission electron microscopy characterization of nanorods in BaNb2O6-doped ErBa2Cu3O7-d films, Appl. Phys. Lett., vol.92, no.11, 112503, 2008.01.
311. A. Ichinose, K. Naoe, T. Horide, K. Matsumoto, R. Kita, M. Mukaida, Y. Yoshida and S. Horii, Microstructures and critical current densities of YBCO films containing structure-controlled BaZrO3 nanorods, Supercond. Sci. Technol., 20, p. 616-620, 2007.05.
312. S. Horii, K. Yamada, H. Kai, A. Ichinose, M. Mukaida, R. Teranishi, R. Kita, K. Matsumoto, Y. Yoshida, J. Shimoyama and K. Kishio, Introduction of c-axis-correlated 1D pinning centers and vortex bose glass in Ba?Nb?O-doped ErBa2Cu3Oy films, Supercond. Sci. Technol., 20, p. 616-620, 2007.05.
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314. T. Horide, K. Matsumoto, A. Ichinose, M. Mukaida, Y. Yoshida and S. Horii, Matching field effect of the vortices in GdBa2Cu3O7-d thin film with gold nanorods, Supercond. Sci. Technol., 20, p. 303-306, 2007.05.
315. P. Mele, K. Matsumoto, T. Horide, A. Ichinose, M. Mukaida, Y. YOSHIDA and S. Horii, Enhanced high-field performance in PLD films fabricated by ablation of YSZ-Added YBa2Cu3O7-x target, Supercond. Sci. Technol., 20, p. 244-250, 2007.05.
316. S. Horii, A. Ichinose, Y. Ichino, T. Ozaki, Y. Yoshida, K. Matsumoto, M. Mukaida, J. Shimoyama and K. Kishio, Critical current properties and microstructures in impurity-doped ErBa2Cu3Oy films, Physica C, 463-465, p. 922-926, 2007.05.
317. Y. Shingai, M. Mukaida, R. Teranishi, N. Mori, K. Yamada, R. Kita, S. Kato, A. Ichinose, S. Horii, Y. Yoshida, K. Matsumoto, S. Awaji, K. Watanabe, M. Nanba and A. Saito, Influence of amount of BaZrO3 doping into ErBa2Cu3O7-d films, Physica C, 463-465, p. 909-913, 2007.05.
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319. S. Yasunaga, M. Mukaida, K. Matsumoto, Y. Yoshida, A. Ichinose, S. Horii, R. Kita, S. Kato, R. Teranishi, K. Yamada and N. Mori, Improvement of superconducting properties by BaZrO3 doping into ErBa2Cu3O7-d thin films, Physica C, 463-465, p. 900-903, 2007.05.
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321. K. Yamada, N. Mori, K. Tada, T. Tanaka, R. Teranishi, M. Mukaida, S. Toh, K. Kaneko, T. Izumi and Y. Shiohara, Transmission electron microscopy studies of YBCO films fabricated by advanced TFA-MOD process, Physica C, 463-465, p. 717-721, 2007.05.
322. T. Horide, K. Matsumoto, Y. Yoshida, M. Mukaida, A. Ichinose and S. Horii, The limitation mechanism of JC?θ characteristics in YBa2Cu3O7?x thin film with a single low angle grain boundary, Physica C, 463-465, p. 678-681, 2007.05.
323. A. Ichinose, M. Mukaida, P. Mele, T. Horide, K. Matsumoto, R. Kita, Y. Yoshida and S. Horii, Microstructures of BaZrO3-doped ErBa2Cu3Oy films fabricated by different BaZrO3 supply, Physica C, 463-465, p. 657-660, 2007.05.
324. P. Mele, K. Matsumoto, T. Horide, A. Ichinose, M. Mukaida, Y. Yoshida and S. Horii, YBa2Cu3O7?x + YSZ mixed films with enhanced critical current densities in magnetic field, Physica C, 463-465, p. 653-656, 2007.05.
325. T. Ozaki, Y. Yoshida, M. Miura, Y. Ichino, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii and M. Mukaida, Current-carrying property and microstructure of multilayered Sm1+xBa2?xCu3Oy thick films, Physica C, 463-465, p. 649-652, 2007.05.
326. S. Funaki, Y. Yoshida, Y. Ichino, M. Miura, Y. Takai, K. Matsumoto, A. Ichinose, M. Mukaida and S. Horii, Enhancement of dislocation density in YBa2Cu3Oy thin films prepared by low temperature growth technique, Physica C, 463-465, p. 644-648, 2007.05.
327. Y. Ichino, Y. Yoshida, M. Miura, Y. Takai, K. Matsumoto, M. Mukaida, A. Ichinose, S. Horii, S. Awaji and K. Watanabe, Flux pinning properties in high magnetic field and low temperature of SmBa2Cu3Oy thin films, Physica C, 463-465, p. 639-643, 2007.05.
328. Y.Yoshida, Y. Ichino, M. Miura, T. Ozaki, Y. Takai, K. Matsumoto, A. Ichinose, M. Mukaida and S. Horii, Enhanced superconducting performances in nanostructured SmBCO coated conductor, Physica C, 463-465, p. 633-638, 2007.05.
329. T. Nakamura, R. Kita, O. Miura, A. Ichinose, K. Matsumoto, Y. Yoshida, M. Mukaida and S. Horii, Fabrication of GdBa2Cu3Oy films by metal-organic deposition using metal-naphthenates, Physica C, 463-465, p. 540-543, 2007.05.
330. T. Tanaka, K. Tada, N. Mori, K. Yamada, R. Teranishi, M. Mukaida, Y. Shiohara, T. Izumi and J. Matsuda, Formation process of microstructure and properties of YBCO film fabricated by advanced TFA-MOD method, Physica C, 463-465, p. 527-531, 2007.05.
331. N. Mori, Y. Nakahara, K. Ogi and M. Mukaida, In situ observation and analysis of faceted crystal growth process in REBCO superconductive oxide, Physica C, 463-465, p. 330-334, 2007.05.
332. T. Horide, K. Matsumoto, A. Ichinose, M. Mukaida, Y. Yoshida and S. Horii, Magnetic-field-induced crossover from flux-flow to Josephson-junction behavior in a highly transparent weak link, Phys. Rev. B, 75, art. No. 20504, 2007.05.
333. R. Kita, T. Nakamura, A. Ichinose, O. Miura, K. Matsumoto, Y. Yoshida, M. Mukaida and S. Horii, Growth of GdBa2Cu3Oy films prepared by BaF2 process without water vapor, Modern Phys. Lett. B, 21, p. 1377-1382, 2007.05.
334. K. Yamada, A. Ichinose, Y. Tomokiyo, Y. Shingai, K. Matsumoto, Y. Yoshida, S. Horii, R. Kita, S. Toh, K. Kaneko, N. Mori and M. Mukaida, Moire fringe analysis of BaZrO3 nanorods in ErBa2Cu3O7-d films, Jpn. J. Appl. Phys., Part 1, 46, p. 708-711, 2007.05.
335. M. Miura, Y. Yoshida, T. Ozaki, Y. Ichino, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii and M. Mukaida, Enhanced critical current under a magnetic field in Sm1+xB2-xCu3Oy thick films prepared using low-temperature growth technique, Jpn. J. Appl. Phys., 46, p. L807-L809, 2007.05.
336. M. Miura, Y. Yoshida, T. Ozaki, Y. Ichino, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii and M. Mukaida, The mechanism for the formation of a-axis phase in high-Jc Sm1+xBa2-xCu3Oy thick films prepared by low temperature growth technique, JOURNAL OF THE JAPAN INSTITUTE OF METALS, 71, p. 999-1005, 2007.05.
337. T. Horide, K. Matsumoto, A. Ichinose, M. Mukaida, Y. Yoshida and S. Horii, Vortex pinning by gold nanorods in GdBa2Cu3O7-d thin films, IEEE Trans. Appl. Supercond., 17, Part 3, p. 3729?3732, 2007.05.
338. P. Mele, K. Matsumoto, T. Horide, A. Ichinose, M. Mukaida, Y. Yoshida and S. Horii, Fabrication of thick YBa2Cu3O7-X films on optimized SrTiO3 buffered-MgO single crystals, IEEE Trans. Appl. Supercond., 17, Part 3, p. 3713?3716, 2007.05.
339. A. Ichinose, M. Mukaida, S. Horii, R. Kita, K. Matsumoto and Y. Yoshida, Microstructures of high-TC superconducting films introduced zero-dimensional and one-dimensional artificial pinning centers, IEEE Trans. Appl. Supercond., 17, Part 3, p. 3701?3704, 2007.05.
340. M. Mukaida, T. Horide, Y. Shingai, A. Ichinose, K. Matsumoto, S. Horii, R. Kita, Y. Yoshida, S. Awaji, K. Watanabe, R. Teranishi, K. Yamada and N. Mori, Microstructure and JC characteristics of Er123 films with artificial pinning centers, IEEE Trans. Appl. Supercond., 17, Part 3, p. 3688?3691, 2007.05.
341. R. Teranishi, J. Matsuda, K. Nakaoka, T. Izumi, Y. Shiohara, N. Mori and M. Mukaida, High production rate process of YBCO coated conductors by TFA-MOD process, IEEE Trans. Appl. Supercond., 17, Part 3, p. 3317?3320, 2007.05.
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343. T. Ozaki, Y. Yoshida, M. Miura, Y. Ichino, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii and M. Mukaida, Enhancement of critical current in Sm1+xBa2-xCu3Oy multilayer films with the insertion of Sm-rich phase, IEEE Trans. Appl. Supercond., 17, Part 3, p. 3270?3273, 2007.05.
344. M. Miura, Y. Yoshida, T. Ozaki, Y. Ichino, M. Mutoh, S. Funaki, T. Takai, K. Matsumoto, A. Ichinose, S. Horii, M. Mukaida, S. Awaji and K. Watanabe, Magnetic field dependence of critical current density and microstructure in Sm1+xBa2-xCu3Oy films on metallic substrates, IEEE Trans. Appl. Supercond., 17, Part 3, p. 3247?3250, 2007.05.
345. M. Haruda, T. Fujiyoshi, T. Suekichi, K. Dezaki, M. Mukaida, K. Matsumoto, Y. Yoshida, A. Ichinose, S. Horii, Flux Pinning Properties of ErBa2Cu3Oy thin films with BaZO3 nanorods, Supercond. Sci. Technol., 19, 803-807, 2006.05.
346. P. Mele, K. Matsumoto, T. Horide, O.Miura, A. Ichinose, M. Mukaida, Y. Yoshida and S. Horii, Tuning of critical current in YBa2Cu3O7-x thin films by control of Y2O3 nanoislands size and density on annealed SrTiO3 substrates, Supercond. Sci. Technol., 19, 44-50, 2006.05.
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348. 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-δ superconducting thin films, Physica C, 445-448, 845-848, 2006.05.
349. Y. Shingai, T. Abe, M. Mukaida, R. Kita, Y. Yoshida, A. Ichinose, S. Horii, K. Matsumoto, A. Saitob, K. Yamada, N. Mori, Improvement of superconducting properties by BaTiO3 doping into ErBa2Cu3O7-δ films, Physica C, 445-448, 841-844, 2006.05.
350. S. Horii, Y. Ichino, Y. Yoshida, K. Matsumoto, M. Mukaida, A. Ichinose, J. Shimoyama, K. Kishio, Dilute Co-doping effects on critical current properties in PLD-ErBa2Cu3Oy films, Physica C, 445-448, 837-840, 2006.05.
351. M. Mukaida, A. Saito, R. Kita, K. Matsumoto, A. Ichinose, Y. Yoshida, S. Horii, K. Yamada and N. Mori, Surface resistance of RE123 films with artificial pinning centers, Physica C, 445-448, 828-832, 2006.05.
352. Y. Ichino, T. Ozaki, Masashi Miura, Yutaka Yoshida, Yoshiki Takai, Kaname Matsumoto, Masashi Mukaida, Ataru Ichinose, Shigeru Horii, Comparative study of carrier concentration and reciprocal space mapping in SmBa2Cu3Oy thin films with high critical current density, Physica C, 445-448, 689-693, 2006.05.
353. K. Yamada, A. Ichinose, Y. Shingai, K. Matsumoto, Y. Yoshida, S. Horii, R. Kita, S. Toh, K. Kaneko, N. Mori, M. Mukaida, TEM observation of ErBa2Cu3O7-δ films with BaZrO3 artificial pinning centers, Physica C, 445-448, 660-664, 2006.05.
354. T. Horide, K. Matsumoto, H. Adachi, D. Takahara, K. Osamura, A. Ichinose, M. Mukaida, Y. Yoshida and S. Horii, Evaluation of Metallic Nanoparticles in REBa2Cu3O7-δ (RE=Y, Gd) Thin Films by Small Angle X-Ray Scattering, Physica C, 445-448, 652-655, 2006.05.
355. P. Mele, K. Matsumoto, T. Horide, O. Miura, A. Ichinose, M. Mukaida, Y. Yoshida and S. Horii, Critical current enhancement in PLD YBa2Cu3O7-x films using artificial pinning centers, Physica C, 445-448, 648-651, 2006.05.
356. M. Miura, Y. Ichino, Y. Yoshida, Y. Takai, K. Matsumoto, A. Ichinose, M. Mukaida, S. Horii, ADDITION OF LOW-Tc-NANOPARTICLES DISPERSIONS TO ENHANCE FLUX PINNING OF Sm1+xBa2-xCu3Oy FILMS, Physica C, 445-448, 643-647, 2006.05.
357. Y. Yoshida, K. Matsumoto, M. Miura, Y. Ichino, Y. Takai, A. Ichinose, M. Mukaida, S. Horii, Controlled nanoparticulate flux pinning structures in RE1+xBa2-xCu3Oy films, Physica C, 445-448, 637-642, 2006.05.
358. K. Yokoyama, R. Kita, A. Ichinose, O. Miura, K. Matsumoto, Y. Yoshida, M. Mukaida, S. Horii, SUPERCONDUCTING PROPERTIES OF REBa2Cu3Oy (RE=Y and Gd) FILMS PREPARED BY THE BaF2 PROCESS, Physica C, 445-448, 587-589, 2006.05.
359. R. Kita, T. Naito, A. Shiraishi, K. Oidaira, O. Miura, K. Matsumoto, Y. Yoshida, M. Mukaida, S. Horii, A. Ichinose, EFFECT OF Ta2O5 ADDITION ON THE SUPERCONDUCTING PROPERTIES OF REBa2Cu3Oy, Physica C, 445-448, 391-394, 2006.05.
360. M. Miura, Y Y. Yoshida. Ichino, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii, M. Mukaida, Enhancement of Flux-Pinning in Epitaxial SmBCO Films by Introduction of Low-Tc Nanoparticles, Jpn. J. Appl. Phys., 45, L11-L13, 2006.05.
361. Y. Ichino , H. Matsuo, Y. Yoshida , Y. Takai, K. Matsumoto, M. Mukaida , A. Ichinose , S. Horii, Possibility of High Deposition Rate in SmBa2Cu3Oy Films Prepared Using the Vapor-Liquid-Solid Growth Mode, Jpn. J. Appl. Phys., 45, 758-760, 2006.05.
362. M. Miura, Y. Yoshida, Y. Ichino, T. Ozak, Y. Takai, K. Matsumoto, A. Ichinose, Shigeru Horii and M. Mukaida, Dislocation Density and Critical Current Density of Sm1+xBa2-xCu3Oy Films Prepared by Various Fabrication Processes , Jpn. J. Appl. Phys., 45, L701-L704, 2006.05.
363. Shigeru Horii, Yusuke Ichino, Toshiki Ozaki, Kaname Matsumoto, Yutaka Yoshida, Masashi Mukaida, Ataru Ichinose, Jun-ichi Shimoyama, Koji Kishio, c-axis Correlated Vortex Pinning Center Induced by Dilute Co-doping in Pulsed-Lase-deposition-ErBa2Cu3Oy films, Jpn. J. Appl. Phys., 45, L617-L620, 2006.05.
364. Masashi Miura, Yutaka Yoshida, Yusuke Ichino, Toshinori Ozak, Yoshiaki Takai, Kaname Matsumoto, Ataru Ichinose, Shigeru Horii and Masashi Mukaida, Dislocation Density and Critical Current Density of Sm1+xBa2-xCu3Oy Films Prepared by Various Fabrication Processes, Jpn. J. Appl. Phys., 45, L701-L704, 2006.05.
365. T.Horide, K.Matsumoto, Y.Yoshida, M.Mukaida, A.Ichinose, S.Horii, Combined effect of a single grain boundary and artificial pinning centers on the critical current density in a YBa2Cu3O7?d thin film, Appl. Phys. Lett., 89, 172505, 2006.05.
366. M. Mukaida, T. Horide, R. Kita, S. Horii, A. Ichinose, Y. Yoshida, O. Miura, K. Matsumoto, K. Yamada, N. Mori, Critical Current Density Enhancement Around a Matching Field in ErBa2Cu3O7-δ Films with BaZrO3 Nano-Rods, Jpn. J. Appl. Phys., 10.1143/JJAP.44.L952, 44, 28-32, L952-L954, 44, L952 - L954, 2005.08.
367. M. Miura, M. Itoh, Y. Yoshida, Y. Ichino, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii and M. Mukaida, In-plane alignment and superconducting properties in high-Jc Sm1+xBa2-xCu3O6+δ thin films, Physica C, 426-431, 985-989, 2005.05.
368. R. Kita, K. Nezu, K. Yokoyama, K. Matsumoto, Y. Yoshida, M. Mukaida, S. Horii, A. Ichinose, Effect of AZrO3 and AWO4 (A=Ba, Sr and Ca) addition on the superconducting properties of ErBa2Cu3Oy, Physica C, 426-431, 550-555, 2005.05.
369. N. Sekiya, M. Mukaida, A. Saito, S. Hirano and S. Ohshima, Examination of a microwave sensing system using superconducting device, Physica C, 426-431, 1622-1627, 2005.05.
370. T. Ohazama, M. Mukaida, S. Horii, A. Saito, R. Kita, A. Ichinose, Y. Yoshida, K. Matsumoto, S. Ohshima, Low surface resistance Zn-doped ErBa2Cu3O7-δ thin films, Physica C, 426-431, 1611-1615, 2005.05.
371. K. Kitamura, Y. Noguchi, M. Mukaida, H. Yamasaki, Y. Nakagawa, S. Hirano, S. Ohshima, Temperature and dc magnetic field dependence of the surface resistance in HTS films, Physica C, 426-431, 1606-1610, 2005.05.
372. M. Miura, M. Mukaida, A. Saito, A. Ichinose, S. Horii, R. Kita, Y. Yoshida, K. Matsumoto, K. Koike and S. Ohshima, Growth of EuBa2Cu3O7-δ films under an ozone atmosphere, Physica C, 426-431, 1429-1433, 2005.05.
373. Y. Shingai, M. Mukaida, K. Matsumoto, Y. Yoshida, A. Ichinose, S. Horii, K. Koike, F. Hirose, A. Saito and S. Ohshima, Growth and characterization of a-axis oriented ErBa2Cu3O7-δ films using double buffer layers, Physica C, 426-431, 1424-1428, 2005.05.
374. M. Ito, M. Mukaida, T. Ohazama, R. Kita, A. Ichinose, S. Horii, A. Saito, K. Matsumoto, Y. Yoshida, K. Koike, F. Hirose, S. Ohshima, Microstructure of ErBa2Cu3O7-δ films with BaZrO3 dispersion pinning centers for high JC applications, Physica C, 426-431, 1415-1418, 2005.05.
375. A. Saito, K. Takeishi, Y. Takano, T. Nakamura, M. Yokoo, M. Mukaida, S. Hirano and S. Ohshima, Rapid and simple measurement of critical current density in HTS thin films using a permanent magnet method, Physica C, 426-431, 1122-1126, 2005.05.
376. P. Mele, K. Matsumoto, T. Horide, O. Miura, A. Ichinose, M. Mukaida, Y. Yoshida and S. Horii, Control of Y2O3 nanoislands deposition parameters in order to induce defects formation and its influence on the critical current density of YBCO films, Physica C, 426-431, 1108-1112, 2005.05.
377. K. Matsumoto, T. Horide, P. Mele, Y. Yoshida, M. Mukaida, A. Ichinose and S. Horii, Effects of artificial pinning centers on vortex pinning in high-temperature superconducting films, Physica C, 426-431, 1091-1095, 2005.05.
378. Y. Yoshida, K. Matsumoto, M. Miura, Y. Ichino, Y. Takai, A. Ichinose, M. Mukaida and S. Horii, JC Characteristics in high magnetic field and microstructure of RE1+xBa2-xCu3O6+y films, Physica C, 426-431, 1043-1050, 2005.05.
379. S. Horii, M. Mukaida, Y. Ichino, K. Matsumoto, T. Ohazama, A. Ichinose, Y. Yoshida, J. Shimoyama and K. Kishio, Oxygen post-annealing effects on critical current properties of PLD-ErBa2Cu3Oy films grown at several substrate temperatures, Physica C, 426-431, 1015-1020, 2005.05.
380. M. Mukaida, M. Miura, A. Ichinose, S. Horii, K. Matsumoto, Y. Yoshida, K. Koike, Y. Takahashi, A. Saito and S. Ohshima, Crystal distortion associated with ortho-tetra transition of REBa2Cu3Ox films, Physica C, 426-431, 1010-1014, 2005.05.
381. R. Honda, Y. Ichino, Y. Yoshida, Y. Takai, K. Matsumoto, A. Ichinose, R. Kita, M. Mukaida and S. Horii, Effect of substituted rare earth element in (Yb1-xNdx)Ba2Cu3Oy thin film on growth orientation and superconducting properties, Physica C, 426-431, 1005-1009, 2005.05.
382. Y. Yoshida, K. Mastumoto, Y. Ichino, M. Itoh, A. Ichinose, S. Horii, M. Mukaida, Y. Takai, High Critical Current Density in High Fields in Epitaxial Films of SmBa2Cu3O7-x, Jpn. J. Appl. Phys. Express Letter, 44, L129-L132, 2005.05.
383. M. Mukaida, M. Miura, A. Ichinose, K. Matsumoto, Y. Yoshida, S. Horii, A. Saito, F. Hirose, Y. Takahashi, S. Ohshima, Hetero-epitaxial growth of CeO2 films on MgO substrates, Jpn. J. Appl. Phys., 44, L318-L321, 2005.05.
384. T. Horide, K. Matsumoto, Y. Yoshida, M. Mukaida, A. Ichinose, S. Horii and K. Osamura, Anisotropy and Lorentz-Force Dependences of Critical Current Density in C-Axis-Oriented YBa2Cu3O7-δ Thin Film, Jpn. J. Appl. Phys., 44, L111-L113, 2005.05.
385. K. Matsumoto, T. Horide, P. Mele, A. Ichinose, S. Horii, Y. Yoshida, M. Mukaida, K. Osamura, Jc enhancement in YBa2Cu3Ox thin films by introduction of one-dimensional artificial pinning centers, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15, 3774-3777, 2005.05.
386. T. Horide, K. Matsumoto, A. Ichinose, Y. Yoshida, S. Horii, M. Mukaida, K. Osamura, Angular dependence of critical current density in Y-Ba-Cu-O thin films, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15, 3734-3737, 2005.05.
387. Y. Ichino, R. Honda, M. Miura, M. Itoh, Y. Yoshida, Y. Takai, K. Matsumoto, M. Mukaida, A. Ichinose, S. Horii, Microstructure and field angle dependence of critical current densities and microstructure in REBa2Cu3Oy thin films prepared by PLD method, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15, 3730-3733, 2005.05.
388. A. Ichinose, K. Matsumoto, M. Mukaida, Y. Yoshida, S. Horii, S. Akita, Microstructure of high-Tc superconducting films having artificial pinning centers, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15, 3718-3721, 2005.05.
389. A. Saito, M. Shirakawa, K. Kitamura, Y. Noguchi, M. M ukaida, H. Yamasaki, Y. Nakagawa, S. Ohshima, Relationship between surface resistance and critical current density of HTS thin films in a DC magnetic field, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15, 3696-3699, 2005.05.
390. A. Saito, M. Shirakawa, K. Kitamura, Y. Noguchi, M. M ukaida, H. Yamasaki, Y. Nakagawa, S. Ohshima, Dependence of surface resistance in HTS thin films on a DC magnetic field, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15, 3692-3695, 2005.05.
391. M. Miura, M. Itoh, Y. Ichino, Y. Yoshida, Y. Takai, K. Matsumoto, A. Ichinose, S. Horii, M. Mukaida, Effect of Sm/Ba substitution on the Jc in magnetic field of SmBCO thin films by low temperature growth technique, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15, 3078-3081, 2005.05.
392. Y. Nakamura, Y. Isozaki, M.Miura, T. Kuroiwa, Y.Yoshida, K. Matsumoto, A. Ichinose, S. Horii, M. Mukaida, S. Ohshima, YBCO thin films on TiO2 buffer layer deposited by RF magnetron sputtering, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15, 3028-3030, 2005.05.
393. S. Ohshima, M. Shirakawa, T. Nishimura, A. Saito, M. M ukaida, Hetero-epitaxial growth of YBCO thin films on the A-cut plane sapphire substrates, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15, 2985-2988, 2005.05.
394. Y. Shingai, M. Mukaida, A. Ichinose, S. Horii, Y. Yoshida, K. Matsumoto, F. Hirose, K. Koike, A. Saito, S. Ohshima, Fabrication of a/c axes oriented grain boundaries in YBCO films by selective growth, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15, 2935-2938, 2005.05.
395. S. Ohshima, K. Takeishi, A. Saito, M. M ukaida, Y. Takano, T. Nakamura, I. Suzuki, M. Yokoo, A simple measurement technique for critical current density by using a permanent magnet, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15, 2911-2914, 2005.05.
396. Y. Yoshida, Y. Ichino, M. Miura, Y. Takai, K. Masumoto, A. Ichinose, S. Horii, M. Mukaida, High critical current density in high field in Sm1+xBa2-xCu3O6+y thin films, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15, 2727-2730, 2005.05.
397. K. Matsumoto, D. Takahara, T. Horide, A. Ichinose, S. Horii, Y. Yoshida, M. Mukaida, K. Osamura, High-Jc Gd-Ba-Cu-O epitaxial films prepared by pulsed laser deposition, IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, 15, 2719-2722, 2005.05.
398. F. Hirose, K. Kurita, Y. Takahashi, M. Mukaida, Operation mechanism on SiGe/Si/Si PIN diodes explained using numerical simulation, ELECTROCHEMICAL AND SOLID STATE LETTERS, 8 (7), G160-G163, 2005.05.
399. M. Mukaida, M. Ito, R. Kita, S. Horii, A. Ichinose, M. Matsumoto, Y. Yoshida, A. Saito, K. Koike, F. Hirose, S. Ohshima, Reduction of surface resistance of ErBa2Cu3O7-δ films by BaZrO3 nano-particle inclusion, Jpn. J. Appl. Phys. Express Letter, 43, L1623 - L1625, 2004.12.
400. M. Itoh, Y. Ichino, M. Miura, Y. Yoshida, Y. Takai, K. Matsumoto, A. Ichinose, M. Mukaida, S. Horii, Low temperature growth of high-Jc Sm1+xBa2-xCu3Oy films, Physica, C 412-414, 833-837, 2004.05.
401. A. Saito, H. Shimakage, A. Kawakami, Z. Wang, S. Kuroda, H. Abe, M. Naito, W. J. Moon, K. Kaneko, M. Mukaida, S. Ohshima, XRD and TEM study of as-grown MgB2 thin films deposited on r- and c-plane sapphire substrates, Physica, 10.1016/j.physc.2003.12.100, 412, 1366-1370, C 412-414, 1366-1370, 2004.05.
402. A. Ichinose, Y. Yamamoto, M. Mukaida, A. Kikuchi, K. Tachikawa, S. Akita, K. Inoue, K. Matsumoto, Y. Yoshida, S. Horii, A. Saito, , Preparation of YBa2Cu3O7-x films on cap-layer-buffered MgO substrates using precursor films deposited from Y BaF2 and Cu, Physica, C 412-414, 1321-1325, 2004.05.
403. Y. Yamamoto, M. Mukaida, K. Matsumoto, Y. Yoshida, A. Ichinose, S. Horii, A. Saito, S. Ohshima, Evaluation of Buffer Materials for Fluorine Contained Solid Phase Epitaxy of 123 Films on MgO Substrates, Physica, C 412-414, 1316-1320, 2004.05.
404. S. Horii, M. Mukaida, K. Matsumoto, T. Ohazama, A. Ichinose, Y. Yoshida, J. Shimoyama, K. Kishio, Post-annealing effects of superconducting properties on ErBa2Cu3Oy films fabricated by pulsed laser deposition, Physica, C 412-414, 1306-1309, 2004.05.
405. T. Ohazama, M. Mukaida, A. Ichinose, K. Matsumoto, Y. Yoshida, S. Horii, A. Saito, S. Ohshima, Growth of High-Quality ErBa2Cu3O7-δ Thin Films for The Introduction of Artificial Pinning Centers, Physica, C 412-414, 1301-1305, 2004.05.
406. Y. Shingai, M. Mukaida, K. Matsumoto, Y. Yoshida, A. Ichinose, S. Horii, S. Ohshima, Selective Preferred Orientation control of YBa2Cu3O7-δ Films on a Substrate, Physica, C 412-414, 1296-1300, 2004.05.
407. K. Matsumoto, T. Horide, K. Osamura, A. Ichinose, M. Mukaida, Y. Yoshida, and S. Horii, Flux Pinning Properties of YBCO Thin Films Deposited on SrTiO3(100) and MgO(100) Substrates, Physica, C 412-414, 1291-1295, 2004.05.
408. M. Shirakawa, M. Miura, T. Ohazama, Y. Shingai, A. Saito, M. Mukaida, S. Ohshima, Fabrication and characterization of YBCO thin film on CeO2/ a-plane sapphire substrate, Physica, C 412-414, 1277-1280, 2004.05.
409. K. Matsumoto, T. Horide, K. Osamura, A. Ichinose, M. Mukaida, Y. Yoshida, and S. Horii, Enhancement of Critical Current Density of YBCO Films by Introduction of Artificial Pinning Centers due to the Distributed Nano-Scaled Y2O3 Islands on Substrates, Physica, C 412-414, 1267-1271, 2004.05.
410. S. Horii, A. Ichinose, M. Mukaida, K. Matsumoto, T. Ohazama, Y. Yoshida, J. Shimoyama, K. Kishio, Enhancement of critical current density on ErBa2Cu3Oy thin films by post-annealing, Jpn. J. Appl. Phys. Part II, 43, L1223-L1225, 2004.05.
411. L. Zhang, M. Moriya, T. Kobayashi, M. Mukaida, T. Goto, Sputtering conditions and properties of in-plane-aligned Y-Ba-Cu-O films for devices application, IEICE transactions on Electronics, E87-C, 202-205, 2004.05.
412. M. Mukaida, Y. Yamazaki, Y. Shingai, S. Makino, M. Kusunoki, A. Saito, and S. Ohshima, Surface resistance of YBa2Cu3O7-δ thin films on MgO lattice matched BaZrO3 buffer layers, Supercond. Sci. Tech., 17, 337- 341, 2003.05.
413. N. Hoshi, S. Kambe, O. Ishii and M. Mukaida, Growth mechanism of Bi2212 whisker from bulk precursor, Physica, C 392-396, 62-65, 2003.05.
414. M. Shirakawa, J. Unno, K. Aizawa, M. Kusunoki, M. Mukaida, and S. Ohshima, Fabrication and characterization of a CeO2 buffer layer on c-plane and tilt-c-plane sapphire substrates, Physica, C 392-396, 1346-1352, 2003.05.
415. Y. Nakamura, S. Kudo, M. Mukaida and S. Ohshima, Dependence of crystalline orientation on film thickness of sputtered YBa2Cu3O7-δ on an MgO substrate, Physica, C 392-396, 1276-1280, 2003.05.
416. M. Kusunoki, M. Inadomaru, D. Kosaka, S. Ohshima, K. Aizawa and M. Mukaida, RS measurement of HTS films in millimeter wave region using dielectric resonator method, Physica, C 392-396, 1241-1244, 2003.05.
417. M. Kusunoki, Y. Takano, K. Nakamura, M. Inadomaru, D. Kosaka, A. Nozaki, S. Abe, M. Yokoo, M. Lorenz, H. Hochmuth, M. Mukaida, and S. Ohshima, Demonstration of surface resistance mapping of large-area HTS films using the dielectric resonator method, Physica, C 383, 374-378, 2003.05.
418. S. Ohshima, M. Kusunoki, M. Inadomaru, M. Mukaida, Y. Tanaka, and Hideo Ihara, Relationship Between the Surface Resistance and Depairing Current Density of Superconductors, IEEE Transactions on Applied superconductivity, 13, 3578- 3580, 2003.05.
419. H. Yamada, K. Moriai, S. Kanno, K. Aizawa, M. Kusunoki, M. Mukaida and S. Ohshima, Correlation Between Vortex Distribution and Temperature in YBCO Films and YBCO-QMG Samples, IEEE Transactions on Applied superconductivity, 13, 3121- 3124, 2003.05.
420. Y. Nakamura, T. Tsuchihata, S. Kudo, T. Kawamata, M. Mukaida, S. Ohshima, Crystallinity and Surface Morphology of YBCO Thin Films Using an Amorphous Buffer Layer Deposited at a Low Temperature, IEEE Transactions on Applied superconductivity, 13, 2717-2720, 2003.05.
421. D. Okai, M. Kusunoki, M. Mukaida, S. Ohshima, Surface resistance measurement of superconducting thin film using probe-coupling-type microstrip line resonator, ELECTRONICS AND COMMUNICATIONS IN JAPAN PART II-ELECTRONICS, 86, 27-35, 2003.05.
422. L. Zhang, M. Moriya, T. Kobayashi, T. Goto and M. Mukaida, Planar intrinsic Josephson junctions with in-plane aligned YBCO films, Supercond. Sci. Tech., 15, 1775- 1777, 2002.05.
423. H. Yamada, K. Moriai, S. Kanno, K. Aizawa, M. Kusunoki, M. Mukaida and S. Ohshima, Observation of vortex distribution in YBCO-QMG samples and YBCO thin films, Physica, C 378-381, 554-559, 2002.05.
424. Y. Nakamura, S. Kudo, M. Mukaida and S. Ohshima, Crystallinity of YBCO thin films on an MgO substrate using an amorphous buffer layer deposited at a low temperature, Physica, C 378-381, 1241-1245, 2002.05.
425. M. Mukaida, S. Sato, Y. Takano, M. Kusunoki and S. Ohshima, Control of grain size by initial growth stage of YBCO thin films, Physica, C 378-381, 1232-1235, 2002.05.
426. M. Kusunoki, M. Inadomaru, S. Ohshima, K. Aizawa, M. Mukaida, M. Lorenz and H. Hochmuth, Dielectric loss tangent of sapphire single crystal produced by edge-defined film-fed growth method, Physica, C 377, 313-318, 2002.05.
427. S. Ohshima, S. Oikawa, T. Noguchi, M. Inadomaru, M. Kusunoki, M. Mukaida H. Yamasaki, Y. Nakagawa, The correlation of the critical current density and surface resistance of thin films, Physica, C 372-376, 671-674, 2002.05.
428. K. Semba, M. Mukaida and A. Matsuda, Characteristic transport properties observed in underdoped YBa2Cu3O6+x, Physica, B-312-313, 74-76, 2002.05.
429. L. Zhang, M. Moriya, T. Kobayashi, M. Mukaida, and T. Goto, Fabrication and properties of planar intrinsic Josephson junctions with in-plane aligned YBCO films, IEICE Transactions on Electronics, E 85-C, 764-768, 2002.05.
430. S. Kanno, T. Kawai, S. Satou, K. Aizawa, M. Kusunoki, M. Mukaida, S. Ohshima, S. Hayashi, T. Nishizaki, and N. Kobayashi., Observation of vortices in the high-temperature superconductor, Physica, C 357, 625-628, 2001.05.
431. KI. Itoh, A. Hashizume, H. Kohmoto, M. Matsuo, T. Endo, and M. Mukaida, Magnetic anisotropy and vortex dynamics in a-oriented YBCO thin film characterized by microwave absorption, Physica, C 357, 477-480, 2001.05.
432. K. Ehata, K. Sato, M. Kusunoki, M. Mukaida, S. Ohshima, Y. Suzuki, and K. Kanao, Development of a miniaturized cooling system for HTS antennas and its seal-off property, Physica, C 357, 1507-1510, 2001.05.
433. T. Kinpara, M. Kusunoki, M. Mukaida, and S. Ohshima, Design of cross-coupled microstrip bandpass filter, Physica, C 357, 1503-1506, 2001.05.
434. M. Mukaida, M. Kusunoki, and S. Ohshima, Ln dependence in Ln2CuO4 buffer layers of c-axis in-plane aligned a-axis oriented YBa2Cu3O7-δ thin film growth, Physica, C 357, 1382-1385, 2001.05.
435. K. Develos, H. Yamasaki, A. Sawa, Y. Nakagawa, and S. Ohshima, and M. Mukaida, Microstructure of YBa2Cu3O7-y films on CeO2-buffered Al2O3, Physica, C 357, 1353-1357, 2001.05.
436. K. Chiba, S. Makino, M. Mukaida, M. Kusunoki and S. Ohshima, Critical thickness of BaSnO3 buffer layer for YBa2Cu3O7-δ thin films on MgO substrates, Physica, C 349, 35-39, 2001.05.
437. S. Ohshima, M. Mukaida, M. Kusunoki, K. Chiba, T. Suzuki, M. Inadomaru, and Y. Takano, Relationship between the surface resistance and crystal orientation of YBCO films, IEEE Transactions on Applied superconductivity, 11, 3493-3496, 2001.05.
438. D. Okai, M. Kusunoki, M. Mukaida, S. Ohshima, New surface resistance measurement Technique of high-temperature superconductors using a probe coupling microstrip line resonator, IEEE Transactions on Applied superconductivity, 11, 3078-3081, 2001.05.
439. K. Chiba, S. Makino, M. Mukaida, M. Kusunoki, S. Ohshima, The effect of lattice matching between buffer layer and YBa2Cu3O7-δ thin film on in-plane alignment of c-axis oriented thin films, IEEE Transactions on Applied superconductivity, 11, 2734-2737, 2001.05.
440. K. Ehata, K. Sato, M. Kusunoki, M. Mukaida, S. Ohshima, Miniaturized cooling systems for HTS antennas, IEEE Transactions on Applied superconductivity, 11, 111-114, 2001.05.
441. M. Mukaida, S. Oikawa, M. Kusunoki and S. Ohshima, High temperature resistance of YBa2Cu3O7-δfilms in various oxygen pressure, Supercond. Sci. Tech., 13, L5-L9., 2000.07.
442. S. Ohshima, K. D. Develos, K. Ehata, M. I. Ali, and M. Mukaida, Fabrication of low surface resistance YBCO films and its application to microwave devices, Physica, C 335, 207-213, 2000.05.
443. K. Semba, A. Matsuda, and M. Mukaida, Carrier-concentration-driven superconductor-to-insulator transition in YBa2Cu3O6+x, Physica, B-281, 904-905, 2000.05.
444. K. D. Develos, M. Mukaida, M. Kusunoki and S. Ohshima, Elimination of a-axis Growth in YBa2Cu3O7-δ Films on CeO2-Buffered Al2O3, Jpn. J. Appl. Phys., 39, 1116-1120, 2000.05.
445. M. Mukaida, J. Sugimoto, S. Sato, M. Kusunoki, and S. Ohshima, Effects of cation mixing on the growth of a-axis oriented YBa2Cu3O7-δ thin films, Advances in Superconductivity XII, Springer-Verlag, Tokyo, 957-959, 2000.05.
446. K. Chiba, D. Kousaka, M. Mukaida, M. Kusunoki and S. Ohshima, Fabrication of double-sided YBa2Cu3O7-δ/ BaSnO3 thin films by laser ablation, Advances in Superconductivity XII, Springer-Verlag, Tokyo, 924-926, 2000.05.
447. M. Inadomaru, D. Kousaka, M. Kusunoki, M. Mukaida and S. Ohshima, Optimum configuration of the antenna to the dielectric resonator to measure the accurate surface resistance of the HTS films, Advances in Superconductivity XII, Springer-Verlag, Tokyo, 1069-1071, 2000.05.
448. K. Ehata, M. I. Ali, K. Sato, M. Kusunoki, M. Mukaida S. Ohshima, Y. Suzuki, and K. Kanao, Development of a miniaturized cooling system for HTS Antennas, Advances in Superconductivity XII, Springer-Verlag, Tokyo, 1066-1068, 2000.05.
449. D. Okai, M. Kusunoki, M. Mukaida and S. Ohshima, Effect of cavity's loss on the measurement accuracy of the surface resistance by micro-strip-line resonator method, Advances in Superconductivity XII, Springer-Verlag, Tokyo, 1063-1065, 2000.05.
450. T. Suzuki, S. Sato, M. Kusunoki, M. Mukaida and S. Ohshima, Microwave surface resistance of YBa2Cu3Oy thin films prepared by inductive coupled plasma sputtering, Advances in Superconductivity XII, Springer-Verlag, Tokyo, 1048-1050, 2000.05.
451. M. Mukaida, Y. Takano, K. Chiba, T. Moriya, M. Kusunoki, and S. Ohshima, A new epitaxial BaSnO3 buffer layer for YBa2Cu3O7δ thin films on MgO substrates, Supercond. Sci. Tech., 12, 890-892, 1999.05.
452. K. D. Develos, M. Mukaida and S. Ohshima, Effect of the CeO2 buffer layer thickness on the microwave properties of YBCO thin films, Supercond. Sci. Tech., 12, 887-889, 1999.05.
453. C. Ludwig, T. Sekinger, J. Kuhl, H. U. Habermeier, M. Tani, K. Sakai, M. Hangyo, S. Miyazawa and M. Mukaida, Electrodynamic c-axis properties of thin films in the THz frequency regime, Physica Status Solidi B-basic research, 213, 405-413, 1999.05.
454. M. Kusunoki, Y. Takano, M. Mukaida, and S. Ohshima, The influence of in-plane 0-45° grain boundary on microwave surface resistance of c-axis YBa2Cu3Oy films on MgO substrates, Physica, C 321, 81-85, 1999.05.
455. K. D. Develos, M. Kusunoki, M. Mukaida, S. Ohshima, Effect of deposition rate on the surface morphology of CeO2 films deposited by pulsed laser deposition, Physica, C 320, 21-30, 1999.05.
456. M. Mukaida, Y. Takano, K. Chiba, M. Kusunoki, and S. Ohshima, In-Plane Orientation of c-axis Oriented YBa2Cu3Ox Films on MgO Substrates, Jpn. J. Appl. Phys., 38, 1945-1948, 1999.05.
457. M. Mukaida, M. Kusunoki, and S. Ohshima, Fabrication and Microstructure of All In-Plane Aligned a-axis Oriented SIS Junctions, Jpn. J. Appl. Phys., 38, 1370-1374, 1999.05.
458. M. Kusunoki, T. Suto, D. Okai, Y. Takano, M. Mukaida and S. Ohshima, Microwave Surface Resistance of YBCO Thin Films on Cerium Oxide Buffer, IEEE Transactions on Applied superconductivity, 9, p. 1932-1935, 1999.05.
459. D. Okai, T. Tomiyama, M. Kusunoki, M. Mukaida, and S. Ohshima, New measurement Technique of the surface resistance RS using the microstripline resonator, Advances in Superconductivity XI, Springer-Verlag, Tokyo, 1259-1261, 1999.05.
460. T. Tomiyama, M. Kusunoki, M. Mukaida, and S. Ohshima, Design and fabrication of cross-coupled microstrip bandpass filters, Advances in Superconductivity XI, Springer-Verlag, Tokyo, 1255-1257, 1999.05.
461. Y. Takano, T. Suto, M. Kusunoki, M. Mukaida, and S. Ohshima, Effect of substrate lattice mismatch on the crystallographic properties of YBa2Cu3Oy thin films for microwave devices, Advances in Superconductivity XI, Springer-Verlag, Tokyo, 1129-1231, 1999.05.
462. M. Mukaida Y. Takano, M. Kusunoki, and S. Ohshima, Elimination of 45-degree grain boundaries in LnBa2Cu3Ox thin films for microwave devices on MgO substrates, Advances in Superconductivity XI, Springer-Verlag, Tokyo, 1125-1127, 1999.05.
463. K. D. Develos, M. Kusunoki, M. Mukaida and S. Ohshima, Influence of the microstructure of a CeO2 buffer layer on the superconducting properties of YBa2Cu3O7-δ on Al2O3, Advances in Superconductivity XI, Springer-Verlag, Tokyo, 1109-1111, 1999.05.
464. M. Mukaida M. Kusunoki, and S. Ohshima, Growth manner of c-axis oriented YBa2Cu3Ox thin films, Advances in Superconductivity XI, Springer-Verlag, Tokyo, 1019-1021, 1999.05.
465. M. Mukaida, Y. Takano, K. Chiba, T. Moriya, M. Kusunoki, S. Ohshima, In-plane Orientation Control of c-axis Oriented YBa2Cu3O7-δ Films on MgO Substrates by BaSnO3 Buffer Layers, Jpn. J. Appl. Phys, 38, L926-L928, 1999.03.
466. S. Miyazawa, M. Mukaida, Transmission Electron Microscope Observations of Interfaces in YBa2Cu3Ox /BaSnO3 / YBa2Cu3Ox trilayers, Jpn. J. Appl. Phys., 37, L949-L952, 1998.05.
467. T. Ishii, M. Mukaida, T. Nishihara, S. Hayashi, M. Shinohara, Identification of Surface Atoms of LiGaO2 (001) substrate for Hexagonal GaN film by Coaxial Impact Collision Ion Scattering Spectroscopy, Jpn. J. Appl. Phys., 37, L672-L674, 1998.05.
468. M. Mukaida, Growth of a-axis oriented YBa2Cu3Ox Films on Gd2CuO4 Buffer Layers, Jpn. J. Appl. Phys., 36, L767-L770, 1997.05.
469. S. Miyazawa, M. Mukaida, and M Sasaura, Thin film crystallinity and substrate materials in atomic graphoepitaxy of YBa2Cu3Ox, Acta Physica Polonica, 92, 85-96, 1997.05.
470. T. Nagashima, S. Harada, M. Hangyo, S. Nakajima, M. Mukaida and S. Miyazawa, Inter-plane electromagnetic response of a-axis oriented YBCO films in millimeter wave region, Physica, C 271, 365-372, 1996.05.
471. T. Tsurumaki, S. Uehara, and M. Mukaida, Dependence of YBa2Cu3O7-xultrathin film surface morphology on substrate and growth temperature, Jpn. J. Appl. Phys., 35, L978-L980, 1996.05.
472. S. Miyazawa and M. Mukaida, Formation of Stacking-Faults in Atomic Graphoepitaxial a-axis YBa2Cu3Ox Thin Films on (100) SrLaGaO4 Substrates, Jpn. J. Appl. Phys., 35, L1177-L1180, 1996.05.
473. M. Tsukada, M. Mukaida and S. Miyazawa, Structural and Dielectric Properties of Ba(Ti1-xSnx)O3 Thin films, Jpn. J. Appl. Phys, 35, 4908-4912, 1996.05.
474. M. Mukaida, S. Miyazawa, C. Klemenz, and H. J. Scheel, Structural characterization of a-axis oriented YBa2Cu3Ox films grown by liquid phase epitaxy, J. Cryst. Growth, 169, 715-721, 1996.05.
475. S. Miyazawa and M. Mukaida, Atomic Graphoepitaxial Model for a-axis oriented YBCO Thin Films, Advances in Superconductivity VIII, Springer-Verlag, Tokyo, 949-954, 1996.05.
476. J. Kobayashi, M. Mukaida, Y. Tazoh, and S. Miyazawa, The effect of active atomic oxygen on preferential orientation axis for YBCO films, Advances in Superconductivity VII, Springer-Verlag, Tokyo, 905-908, 1995.05.
477. M. Mukaida, Transport properties in a-axis oriented Y YBa2Cu3Ox thin films, Advances in Superconductivity VII, Springer-Verlag, Tokyo, 543-546, 1995.05.
478. M. Mukaida, S. Miyazawa, and T. Konaka, Reduction of particles on laser deposited thin films, Trans. Mat. Res. Soc. Jpn., 17, 345-348, 1994.05.
479. Y. Tazoh, M. Mukaida and S. Miyazawa, New Insulating Materials for YBa2Cu3Ox / Insulator/ YBa2Cu3Ox Tunnel Junctions, Physica, C 235-240, 3343-3344, 1994.05.
480. M. Mukaida and S. Miyazawa, Transport anisotropy of in-plane c-axis aligned a-axis oriented YBa2Cu3Ox thin films, Physica, B-194, 2311-2312, 1994.05.
481. M. Mukaida, Broad Resistive Transition in c-axis In-plane Aligned a-axis Oriented YBa2Cu3Ox Thin Films, Phys. Rev., B 50, 7124-7128, 1994.05.
482. M. Mukaida and S. Miyazawa, Fabrication of a-axis oriented YBa2Cu3Ox / PrGaO3/ a-axis oriented YBa2Cu3Ox trilayer films, Jpn. J. Appl. Phys., 33, 2521-2525, 1994.05.
483. Y. Tazoh, J. Kobayashi, M. Mukaida and S. Miyazawa, Fabrication of all-epitaxial high-TC SIS tunnel structures, IEICE Transactions on Electronics, E77-C, 1199-1203, 1994.05.
484. S. Miyazawa and M. Mukaida, Atomic grapho-epitaxy; A growth model for c-axis in-plane aligned a-axis oriented YBa2Cu3Ox thin films, Appl. Phys. Lett., 64, 2160-2162, 1994.05.
485. M. Mukaida, S. Miyazawa, and J. Kobayashi, A QLME Interpretation of a-axis Oriented YBa2Cu3Ox Thin Film Growth, Advances in Superconductivity VI, Springer-Verlag, Tokyo, 979-982, 1994.05.
486. M. Mukaida and S. Miyazawa, Nature of Preferred orientation of YBa2Cu3Ox thin films, Jpn. J. Appl. Phys., 32, 4521-4528, 1993.10.
487. M. Mukaida and S. Miyazawa, In-plane alignment of a-axis oriented YBa2Cu3Ox thin films, Appl. Phys. Lett., 63, 999-1001, 1993.08.
488. S. Miyazawa, M. Sasaura, and M. Mukaida, Single crystal growth of rare-earth gallates and epitactic growth nature of high-TC superconducting YBCO thin films on them, J. Crystal Growth, 128, 704-708, 1993.05.
489. M. Mukaida and S. Miyazawa, Preferential axis control of YBa2Cu3Ox thin films by Quasi-Lattice-Match Engineering, J. Appl. Phys., 74, 1209-1212, 1993.05.
490. Y. Tazoh, J. Kobayashi, M. Mukaida and S. Miyazawa, Key Technology toward high-TC tunnel junctions, Appl. Superconductivity, 2, 1119-1122, 1993.05.
491. M. Mukaida, S. Miyazawa, and J. Kobayashi, Quasi-Lattice-Match Engineering for preferential axis control of YBa2Cu3Ox thin films, Advances in Superconductivity V, Springer-Verlag, Tokyo, 893-896, 1993.05.
492. J. Kobayashi, Y. Tazoh, M. Mukaida, M. Sasaura, and S. Miyazawa, PrGaO3-buffered substrate for Superconducting YBa2Cu3Ox epitaxial films, Advances in Superconductivity V, Springer-Verlag, Tokyo, 865-868, 1993.05.
493. J. Kobayashi, Y. Tazoh, M. Mukaida and S. Miyazawa, All high-TC epitaxial YBa2Cu3Ox / NdGaO3/ YBa2Cu3Ox heterostructures, Physica, C 185-189, 2039-2040, 1992.05.
494. M. Mukaida and S. Miyazawa, Growth and crystallographic analysis of YBa2Cu3Ox thin films on NdGaO3 substrate, Jpn. J. Appl. Phys., 31, 3317-3322, 1992.05.
495. S. Miyazawa, M. Sasaura, and M. Mukaida, Evidence of two-dimensionally Epitaxial growth of YBa2Cu3Ox thin films on lattice-matched NdGaO3 substrate, High TC Superconductor Thin Films, Elsevier Science Publishers B.V., 741-746, 1992.05.
496. M. Mukaida, S. Miyazawa, and M. Sasaura, Superconducting YBa2Cu3Ox thin film growth on a vicinal surface of NdGaO3 substrate, Jpn. J. Appl. Phys., 30, L1474-L1476, 1991.05.
497. M. Mukaida, S. Miyazawa, M. Sasaura, and H. Yonezawa, Epitaxial YBa2Cu3O7-y thin film growth on NdGaO3 substrate by laser ablation, J. Appl. Phys., 69, 3399-3401, 1991.05.
498. M. Sasaura, M. Mukaida, and S. Miyazawa, New substrates PrGaO3 for High TC superconducting YBa2Cu3Ox epitaxial film, Advances in Superconductivity III, Springer-Verlag, Tokyo, 929-932, 1991.05.
499. M. Mukaida, S. Miyazawa, and M. Sasaura, Ultrathin YBa2Cu3Ox films on NdGaO3 substrate by laser ablation, Advances in Superconductivity III, Springer-Verlag, Tokyo, 925 -928, 1991.05.
500. M. Mukaida, S. Miyazawa, M. Sasaura, and K. Kuroda, Preparation of YBa2Cu3Ox high TC thin films on NdGaO3 substrate by laser ablation, Jpn. J. Appl. Phys., 29, L936-l939, 1990.05.
501. M. Sasaura, S. Miyazawa, and M. Mukaida, Thermal expansion coefficients of NdGaO3 single crystal, J. Appl. Phys., 68, 3643-3644, 1990.05.
502. M. Sasaura, M. Mukaida, and S. Miyazawa, New substrates PrGaO3 for High TC superconducting YBa2Cu3Oxepitaxial film, Appl. Phys. Lett., 57, 2728-2729, 1990.05.
503. M. Mukaida, K. Kuroda, and S. Miyazawa, Hall Coefficient of c-axis oriented BiSrCaCuO 107 K films, Appl. Phys. Lett., 55, 1129-1131, 1989.05.
504. M. Mukaida, K. Kuroda, Y. Tazoh, and S. Miyazawa, Preparation and electrical properties of 107K-BiSrCaCuOx superconducting thin films, Advances in Superconductivity I, Springer-Verlag, Tokyo, 609-614, 1989.05.
505. K. Kuroda, M. Mukaida, M. Yamamoto, and S. Miyazawa, Preparation of New High-TC Superconducting Oxide Bi-Sr-Ca-Cu-O Thin Films by Electron Beam Deposition Technique, Jpn. J. Appl. Phys., 27, L625-L627, 1988.05.
506. K. Kuroda, M. Mukaida, and S. Miyazawa, Composition dependence and electrical properties of TC &amp;amp;gt; 100 K BiSrCaCuO Superconducting oxide films prepared by sequential deposition, Jpn. J. Appl. Phys., 27, L2230-L2232, 1988.05.
507. M. Mukaida, M. Yamamoto, Y. Tazoh, K. Kuroda, and K. Hohkawa, Synthesis of Superconducting YbBa2Cu3Ox Thin Films by Electron Beam Deposition, Jpn. J. Appl. Phys., 27, L211-L213, 1988.05.
508. M. Okamoto, K. Takei, S. Kubo, M. Mukaida and K. Miyahara, Critical currents of ion-beam sputtered amorphous beryllium thin film and their application to Abrikosov vortex memory, J. Appl. Phys., 62, 212-215, 1986.05.
509. K. Miyahara, M. Mukaida, and K. Hohkawa, Abrikosov Vortex Memory with Improved Sensitivity and Reduced Write Current Levels, IEEE Transactions on Magnetics, 23, 875-878, 1987.05.
510. S. Kubo, K. Miyahara, and M. Mukaida, Flux pinning in amorphous MoSi films for Abrikosov vortex memory, Advances in Cryo. Engineering Materials, 34, 789-796, 1986.05.
511. K. Miyahara, M. Mukaida and K. Hohkawa, Abrikosov Vortex Memory, Appl. Phys. Lett., 47, 754-756, 1985.05.