| Project/Area Number |
03044025
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| Research Category |
Grant-in-Aid for international Scientific Research
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| Allocation Type | Single-year Grants |
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| Section | Joint Research |
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| Research Institution | Yamagata University |
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Principal Investigator |
OHSHIMA Shigetoshi Yamagata University, 工学部, 助教授 (40124557)
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| Co-Investigator(Kenkyū-buntansha) |
GEERK J. Nuclear research center of Karlsruhe, 主任研究員
LINKER G Nuclear research center of Karlsruhe, 主任研究員
SATO Rikiya Yamagata University, 工学部, 助手 (30187257)
TAKAHASHI Koji Yamagata University, 工学部, 助教授 (00134023)
OKUYAMA Katsuro Yamagata University, 工学部, 教授 (70007011)
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| Project Period (FY) |
1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1991: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | Oxide superconducting films / Sputtering / MOCVD / Surface resistance |
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| Research Abstract |
The realization of high frequency devices using oxide superconductors is very important to prepare small surface resistance films. High quality films have small Rs values. The purpose of joint study between Yamagata University and nuclear research center of Karlsruhe is as follows.
(1) Establishment of the preparation technique for high quality films.
The high quality films are prepared by MOCVD method in Yamagata University, and by magnetron sputtering with a cylindrical target in nuclear research center of Karlsruhe. We get slightly large-area YBCO thin films (50X50mm^2) by MOCVD and epitaxial films by sputtering.
(2) Establishment of the measuring system of surface impedance.
The surface impedance of superconducting films is measured by a strip-line resonating method. The Rsvalues of BSCCO and YBCO films decrease below superconducting transition temperature and the value of BSCCO at superconducting state was about 5mOMEGA. .
(3) Buffer layer
Small dielectric-constant substrates are needed for high frequency devices. The dielectric constant of Si and sapphire is small, however these substrates easily react on YBCO. We study the buffer layer, NdGaO_3, which protect the reaction between substrate and YBCO. We prepared c-axis oriented NdGaO_3 films on Si substrate by sputtering.
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