|Masashi Mukaida||Last modified date：2021.08.16|
Professor / Functional Materials / Department of Materials Science and Engineering / Faculty of Engineering
|Masashi Mukaida||Last modified date：2021.08.16|
|1.||M MUKAIDA, S MIYAZAWA, M SASAURA, H YONEZAWA, EPITAXIAL YBA2CU3O7-Y THIN-FILM GROWTH ON NDGAO3 SUBSTRATE BY LASER ABLATION, JOURNAL OF APPLIED PHYSICS, Vol.69, No.5, pp.3399-3401, 1991.03, As-grown superconducting YBa2Cu3O7-y thin films with various thicknesses were successfully grown on lattice-matched NdGaO3 substrates by ArF laser ablation deposition. An as-grown 2000-angstrom-thick film has a zero-resistance temperature (T(c)) at 90 K and a 170-angstrom-thick film has a T(c) at 88 K. The existence of a thin interfacial diffusion layer between a 170-angstrom-thick film and the substrate was observed by Auger electron spectroscopy. Rutherford backscattering spectroscopy suggest that as-grown Yba2Cu3O7-y films on NdGaO3 substrates are high-quality crystals. It is demonstrated that the NdGaO3 has considerable potential as an electronic substrate material by less interfacial diffusion layer and good crystallinity of grown thin films..|
|2.||NAGASHIMA T, HARADA S, HANGYO M, NAKASHIMA S, MUKAIDA M, MIYAZAWA S, ミリ波領域におけるa-軸配向YBCO膜の面間電磁応答, フィジカC, 10.1016/S0921-4534(96)00569-2, Vol.271, No.3-4, pp.365-372, 1996.11.|
|3.||M Mukaida, S Miyazawa, C Klemenz, HJ Scheel, Structural characterization of a-axis oriented YBa2Cu3Ox films grown by liquid phase epitaxy, JOURNAL OF CRYSTAL GROWTH, 10.1016/S0022-0248(96)00469-1, Vol.169, No.4, pp.715-721, 1996.12, YBa2Cu3Ox films on low-misfit LaxNd1-xGaO3 (110) substrates grown by liquid phase epitaxy (LPE) are investigated in the as-grown state by X-ray diffraction, polarized optical microscopy, atomic force microscopy (AFM), and transmission electron microscopy (TEM). The preferred orientation axis of the film normal to the substrate surface is the a-/b-axis with twins, as observed by theta/2 theta-scan, polarized optical micrographs, and cross-sectional view TEM images. In-plane alignment of the c-axis in the films is confirmed by X-ray phi-scan and plane-view TEM images. Defects running perpendicular to the c-axis direction were clearly observed in the plane-view TEM images. These defects consist of excess CuO chains localized in the BaO-BaO interlayers forming (CuO)(n) layers, similar to that in Y2Ba4Cu8Ox (248 phase)..|
|4.||T Nagashima, S Harada, M Hangyo, S Nakashima, M Mukaida, S Miyazawa, Inter-plane electromagnetic response of a-axis oriented YBCO films in the millimeter-wave region, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/S0921-4534(96)00569-2, Vol.271, No.3-4, pp.365-372, 1996.11, The temperature dependence of the inter-plane complex conductivity sigma(1c) - i sigma(2c) of a-axis oriented YBa2Cu3O7-delta thin films deposited on LaSrGaO4(100) substrates has been measured in the millimeter-wave region by using a Mach-Zehnder type interferometric spectrometer. The value of sigma(1c)(T) increases just below T-c with decreasing temperature as well as the in-plane conductivity sigma(1ab)(T). The increase of sigma(1c)(T) below T-c is due to the strong suppression of the quasi-particle damping, The value of sigma(2c)(T) increases almost linearly with decreasing temperature. The temperature dependence of the magnetic penetration depth lambda(c) is deduced from the measured complex conductivity. it is found that lambda(c)(-2)(T) changes almost linearly with temperature. The linear behavior of lambda(c)(-2)(T) is consistent with the theory in which d-wave superconducting layers are coupled through normal layers..|
|5.||Investigation of the uniformity of both-side YBCO thin films fabricated by inductive conpled plasma sputtering
A fabrication technique for large area and both-side YBa_2Cu_3O_y thin films using inductive conpled plasma sputtering is discussed. The critical temperature Tc and the crystallinity of the film deposited on one side were almost the same as those of the film deposited on the other side. To investigate the uniformity of a film, a 50x50 sq.mm.substrate was cut into 10x10 sq.mm.cells. Thickness variations within 10% were obtained over an area with diameter larger than 40 mm., even when using a 50-mm diameter target. The values of the c-axis length, Tc, and critical current density at 77K were found to range from 1.1683～1.1693nm, 83.0～85.5 K, and 1.7～1.8mA/cm^2, respectively.The film was relatively homogeneous on a large area. On the other hand, the distribution of the Tc's does not correspond with that of the c-axis lengths obtained over various areas of the film. This indicates that microscopic inhomogeneity such as crystallinity or impurity could possibly exist in the film..
|6.||Development of a miniaturized cooling system for HTS antennas and its effects on antenna properties
High Temperature Superconducting (HTS) antenna is expected to have high efficiency and low noise. In order to realize the HTS antenna, consideration on cooling system for antenna is important. We have developed a miniaturized cooling system for HTS antennas of portable size using stirling type cryocooler. It is found that the antenna properties are influenced due to the placement of antenna into the system and antenna gain is enhanced due to lens effect. In this paper, outline of the cooling system and properties of antenna attached to it are reported..
|7.||Evaluation of surface resistance of YBCO thin film made by inductive coupled plasma sputtering.
Microwave surface resistance (Rs) of YBa_2Cu_3O_y (YBCO) thin film prepared by inductive coupled plasma sputtering (ICP) was investigated. The Rs was measured by the dielectric resonator method at 22 GHz. The film was deposited on both side of the LaAlO_3 (LAD) substrate. The Rs of the back side film was lower than first side. It indicates that effective substrate temperature during the secound deposition was higher than that of first deposition. The YBCO was deposited also on the BaSnO_3/MgO substrate. The Rs values of the film was 0.38 mΩ at 35 K and 1.13 mΩ at 77 K. The Rs values scaled to 10 GHz were 0.08 mΩ at 35 K and 0.23 mΩ at 77 K, respectively..
|8.||Examination of measurement accuracy of suface resistance by probe-coupling type microstripline resonator method : the effect of the cavity's shapce on measurement accuracy
The microstripline resonator (MSR) is used for the measurement of surface resistance of superconducting thin film. We have developed a probe-coupling type MSR. By this method, it is possible to measure the surface resistance of thin film without attaching contacts to the film. To obtain the accurate value of surface resistance, it needs the technique that can measure the quality factor accurately. This paper reports the effect of the cavity's shape on measurement accuracy. For accurate measurement of the surface resistance of superconducting thin film, it was found that the positions of the cavity's ceiling and antennas are important parameters..
|9.||The effect of in-plan 45゜misaligned orientation on surface resistance of c-axis YBa_2Cu_3O_y films on MgO substrate
The effect of in-plain misaligned orientation on surface resistance (R_s) of c-axis YBa_2Cu_3O_y(YBCO) films on MgO substrates is discussed. Samples that have various amounts of 45゜grains were prepared using self-template technique. The R_s's were measured by dielectric resonator methods. The results indicated that the internal R_s of the 45゜grain is the same as that of the 0゜grain. Furthermore, R_s at the 45゜-45゜grain boundary is also the same as that of the 0゜-0゜grain boundary. On the other hand, 0゜-45゜grain boundaries lead to increase in R_s. Perfect 0゜in-plane aligned YBCO film showed R_s of 0.60mΩ at 20K and 3.26mΩ at 77K. The R_s's scaled to 10GHz were 0.12mΩ at 20K and 0.67mΩ at 77K, respectively..
|10.||M Mukaida, M Kusunoki, S Ohshima, Fabrication and microstructure of all in-plane aligned a-axis oriented superconductor/insulator/superconductor junctions, JAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS SHORT NOTES & REVIEW PAPERS, 10.1143/JJAP.38.1370, Vol.38, No.3A, pp.1370-1374, 1999.03, All in-plane aligned a-axis oriented YBa2Cu3Ox/Gd2CuO4/YBa2Cu3Ox superconductor/insulator/superconductor (SIS) junction structures are fabricated by a pulsed laser deposition technique and their microstructures are characterized. An insulating barrier of Gd2CuO4 with an atomic graphoepitaxial relation is selected from a lattice-matching point of view for the band c-axes of YBa2Cu3Ox at a deposition temperature of the YBa2Cu3Ox films. Preferred orientations and in-plane alignments of electrodes of YBa2Cu3Ox films and barriers of Gd2CuO4 films are confirmed by X-ray diffraction spectroscopy and an X-ray phi-scan technique. X-ray diffraction measurements revealed that all the YBa2Cu3Ox/Gd2CuO4/YBa2Cu3Ox films are a-axis oriented. The c-axes of the layers are also in-plane aligned..|
|11.||Measurement of Surface Resistance of Large Area Superconducting Films
Experimental errors in the measurement of surface resistance(R_s)of superconductor using the dielectric resonator are discussed. Thermal contract of the dielectric, loss tangent of the dielectric, and the amount of scatter of several measurements in the resonance frequency and the quality factor are investigated. The R_s values of the 3-inch YBa_2Cu_3O_y films are measured using 3 kind of sapphires that have different diameter(3.8, 5.8, 9.5 GHz). Scaled R_s to 10 GHz is almost the same in a film with uniform critical density(J.C). On the other hand, differen R_S values that correspond to the J_c distribution are observed in the film that has lack of uniformity in J_c..
|12.||SCE2000-22 / MW2000-86 Design of Cross-coupled Microstrip Bandpass Filter
High Temperature Superconductor(HTS)with having low surface resistance at microwave band is fablicated to be applied to filters that have low insertion loss and sharp skirt characteristics. And it is expected to be applied to mobile telecommuniction system. We have developed an Elliptic Funution. Elliptic Function filer that allows apir of transmission zeros to be placed at the band edges is less component compaired with normal hairpin filter. This paper presents recent developments of an 8-pole planar HTS bandpass fitler with elliptic function response by Sonnet-EM..
|13.||Improvement of superconducting filter properties using dielectric rod trimming
The superconductig filter properties are affected by the deviation of substrate parameters, for example thickness and the value of dielectric constant and so on. Therefore it is very difficult to obtain a high-performance filter in rare filter. We examined the improvement of superconducting filter properties using dielectric rod trimming. We examined the optimum position and arrangement of sapphire rod. This method was very effective for the improvement of the filter properties, because the sapphire rod can improve the connection parameters between the resonators. However, we found that it is necessary to use a high-dielectric rod in order to shift the resonance frequency more. We compared the change of filter properties using different dielectric trimming rod, εr=20,39 and 42..
|15.||Measurement of dielectric constant of R-,A-,C-plane sapphire substrates and fabrication of YBCO thin films on these substrates.
Sapphire substrates are expected as suitable substrates of superconducting microwave devices, however, there are few reports on anisotropic dielectric constant of the sapphire substrates. Therefore, we examine the temperature dependence of dielectric constant. This paper presents the measured results of dielectric constants of r-, a-, and c-plane sapphire substrates by the cavity resonance method. Also, we have examined the conditions of epitaxial CeO_2 films on these sapphire substrates, and also examined epitaxial growth of YBa_2Cu_3O_<7-δ> films were grown on these CeO_2 buffer layers..
|16.||Oxygen-annealing effects on superconducting properties of ErBa2Cu3Oy thin films fabricated by pulsed laser deposition method
We report crystallographic and electrical properties of ErBa2Cu3Oy/SrTiO3 (Er123/STO) films which were fabricated by the pulsed-laser-deposition (PLD) method in the temperature range of 720similar to780degreesC, and dramatic enhancement of critical current density (Jc) by an oxygen post-annealing process. The PLD Er123/STO films were found to be crystallographically excellent in the deposition temperature region below 770degreesC from the intensity of diffraction peaks of 00l, the pole-figure of a reciprocal (102) plane and microstructures of the surface and the cross-section. Interestingly, in this temperature region, Jc values were clearly increased to the order of 10(10) Am-2 by oxygen post-annealing in comparison with those of the as-grown films (0.3similar to0.6 x 10(10) Am-2). Enhancement of Jc was accomplished in a wide annealing temperature range of 350similar to500degreesC, which is corresponding with an annealing temperature range where the critical temperature shows over 90 K on a polycrystalline sample. On the other hand, Irreversibility fields were almost independent of the annealing temperature. These results indicated that insufficient carrierdoped region was partly existed even in a non-equilibrium process such as the PLD method. Therefore, homogenization of oxygen contents in a whole part of the Er123 film is crucially important for enhancement of critical current properties, which strongly suggests that the oxygen annealing is effective for improvement of functionality of devices in PLD-REBa2Cu3Oy (RE: rare earth elements) thin films..
|17.||P Mele, K Matsumoto, T Horide, O Miura, A Ichinose, M Mukaida, Y Yoshida, S Horii, Tuning of the critical current in YBa2Cu3O7-x thin films by controlling the size and density of Y2O3 nanoislands on annealed SrTiO3 substrates, SUPERCONDUCTOR SCIENCE & TECHNOLOGY, 10.1088/0953-2048/19/1/008, Vol.19, No.1, pp.44-50, 2006.01, We introduced high density columnar defects, as artificial pinning centres (APCs) for quantized vortices, into YBa2Cu3O7-chi (YBCO) films during the film deposition procedure. APCs were introduced perpendicular to the film surface using nanosized Y2O3 islands prepared on SrTiO3 (100) substrates by pulsed laser deposition. Varying the deposition parameters and the substrate annealing conditions allowed strong changes in the shape and density of the Y2O3 islands to be induced. The best performance among the APC samples as compared to the pure YBCO film was obtained for that grown on the Y2O3-deposited substrate with five laser pulses, corresponding, to 0.2 Y2O3 monolayers (ML). Even when the 0.2 ML 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 = 5T)..|
|18.||S. Horii, Y. Ichino, Y. Yoshida, K. Matsumoto, T. Horide, M. Mukaida, A. Ichinose, R. Kita, J. Shimoyama, K. Kishio, Impurity Doping Effects on Critical Current Properties in ErBa2Cu3Oy films, Proc. of 6th Pacific RIM Conference on Ceramic and Glass Technology, Hawaii, Sep. 12-16, 2005. (CD-ROM, 9pages), 2006.09.|
|19.||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-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2008.05.121, Vol.468, No.15-20, pp.1391-1394, 2008.09, We have investigated the stability of BasnO(3), BaZrO3, BaTiO3 and BaNb2O6 in the ErBa2Cu3Oy (Er123) matrix by mixing and sintering powders of Er123 and barium oxides. The degradation of T-c due to the addition of barium oxide was the lowest in the case of BaSnO3 (BSO). BSO-added samples exhibited a T-c above 90 K even for 15 vol% addition and an improved J(c) under a magnetic field. XRD and SEM results indicated that BSO was very stable in the Er123 matrix. The dependence of T-c on BSO addition showed similar trends for the sintered samples and Er123 thin films. It was found that the most stable barium oxide in Er123 superconductors was BaSnO3. (C) 2008 Elsevier B.V. All rights reserved..|
|20.||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-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2008.05.222, Vol.468, No.15-20, pp.1554-1558, 2008.09, Metal organic deposition process using trifluoroacetates (TFA-MOD) is one of the most promising processes to fabricate YBCO film. It has been reported that YBCO films grown by the starting solution with Ba-poor (cation ratio as Y:Ba:Cu = 1:1.5:3) have higher J(C) value and has smaller and less pores than those of the YBCO film with stoichiometric composition. It is important to investigate the growth mechanism of YBCO crystals to obtain a high J(C) film by controlling the crystal structures. In this Study, YBCO films were fabricated under various Ba concentrations in the TFA starting solution, and the influences of Ba composition on the growth process and microstructures were investigated. As a result, the Ba-poor YBCO film with Ba/Y = 1.5 and high J(C) had less a-axis oriented Y123 in comparison with the film with Ba/Y = 2. Furthermore. pores in the Ba-poor film were less than that in the stoichiometric composition film. This decrease of pores in the Ba-poor film was considered to be caused by the smaller size of non-reacted phases especially such as Ba-F rich particles entrapped by growing Y123 in the growing Y123 layer. It is considered that both the reductions of a-axis oriented Y123 and pores were the reasons of improving J(C) values in Ba-poor film. (c) 2008 Elsevier B.V. All rights reserved..|
|21.||Three-dimensional observation of microstructures in Y123 films fabricated by TFA-MOD method
We were successful for three-dimensional imaging of microstructures in YBa2Cu3O7-y (Y123) films fabricated by metal organic deposition using trifluoroacetates (TFA-MOD) method. We have reported previously, that a transmission electron microscopy (TEM) analysis clarified microstructures such as Y123 crystal grains and pores in the Y123 films. In order to derive important parameters for enhancement of superconducting properties of the Y123 films, quantitative analyses of those microstructures are required. Then, control of both pores and a-axis oriented grains distribution in the Y123 films are important. However, general TEM images provide only a two-dimensional projection of a three-dimensional object. An electron tomography is an effective technique for three-dimensional structure analysis of various materials. Cross-sectional view specimen for the three-dimensional electron tomography was prepared by focused ion-beam milling equipped with micro-sampling system. A scanning transmission electron microscopy - annular dark field technique was used for the present three-dimensional electron tomography. For the cross-sectional specimen of fired Y123 films, three-dimensional shapes and distributions of both pores and unreacted phases were observed in reconstructed images. Also, morphologies of the Y123 film surface were clearly seen. © 2009 Elsevier B.V. All rights reserved..
|22.||R. Teranishi, K. Tada, J. Yoshida, K. Yamada, N. Mori, M. Mukaida, M. Inoue, T. Kiss, K. Nakaoka, M. Miura, M. Yoshizumi, T. Izumi, Y. Shiohara, High-J(c) YBCO films using precursors with barium concentration gradient in film thickness by TFA-MOD process, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2009.05.027, Vol.469, No.15-20, pp.1345-1348, 2009.08, YBa2Cu3O7-delta (YBCO) films were grown by using precursor films with barium concentration gradient in film thickness by an advanced metal organic deposition process using trifluoroacetates (TFA-MOD). We have reported previously 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 a starting solution with barium-poor (cation ratio as Y:Ba:Cu = 1:1.53). Then, the barium concentration was increased in the film surface to complete the reaction among these Y and Cu residues and Ba and to increase the Y123 growth thickness for realizing higher J(c) performance. Transmission electron microscopy (TEM) observation showed the increase of film thickness of YBCO grown by the precursors with barium concentration gradient in film thickness, indicating that the reaction between these Y and Cu-oxides and Ba proceeded to form Y 123 phase. Consequently, higher J(c) was obtained for the YBCO film by the precursors mentioned above than that of the YBCO film by the precursors with a constant concentration. Effects of barium concentration gradient in the precursors on the superconducting properties and microstructures in the YBCO film were discussed. (C) 2009 Elsevier B.V. All rights reserved.|
|23.||K. Kawabata, T. Nakamura, R. Kita, O. Miura, A. Ichinose, K. Matsumoto, Y. Yoshida, M. Mukaida, 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-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2009.05.028, Vol.469, No.15-20, pp.1353-1356, 2009.08, (Nd,Eu,Gd)Ba2Cu3Oy (NEG) films were prepared on LaAlO3 single-crystal substrates by metal-organic deposition (MOD) using fluorine-free solutions of metal 2-ethylhexanates (2-EH) or metal naphthenates (MN) with a small amount of trifluoroacetic acids (TFA) added. The addition of TFA to fluorine-free solutions lowered the growth temperatures, promoted crystal growth, and improved the superconducting properties of NEC films. This was similar to the effects observed on the growth of superconducting films by TFA-MOD using metal-trifluoroacetates. We report the successful growth of NEC films with T-c of 92.6 K and J(c) of 0.36 MA/cm(2) without introduction of water vapor. (C) 2009 Elsevier B.V. All rights reserved..|
|24.||R. Kita, N. Hosoya, N. Otawa, S. Kawabata, T. Nakamura, O. Miura, M. Mukaida, K. Yamada, A. Ichinose, K. Matsumoto, M. S. Horii, Y. Yoshida, Effects of RE2O3 (RE = Tm, Sc, Yb) addition on the superconducting properties of ErBa2Cu3Oy, PHYSICA C-SUPERCONDUCTIVITY AND ITS APPLICATIONS, 10.1016/j.physc.2009.01.020, Vol.469, No.15-20, pp.1157-1160, 2009.08, We investigated the effects of added Tm2O3, Sc2O3, and Yb2O3 on the superconducting properties of sintered Er123 samples. Tm2O3 addition caused the least T-c degradation, exhibiting a T-c above 90 K even for 17 vol% addition. Samples with added Sc2O3 maintained a Tc at above 90 K up to an addition of 7.2 vol%, while Yb2O3-containing samples showed a monotonic decrease in T, with increased vol% of added Yb2O3. Tm2O3-containing samples exhibited a slight increase in J(c)(0.1 T)/J(c)(0) and had constant J(c) values even for 17 vol% addition. XRD and SEM results indicate that the Tm2O3 is very stable in the superconducting matrix. (C) 2009 Elsevier B.V. All rights reserved..|