| Project/Area Number |
11450333
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
無機工業化学
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| Research Institution | Yamanashi University |
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Principal Investigator |
TANAKA Isao Yamanashi Univ., Faculty of Engineering, Associate Professor, 工学部, 助教授 (40155114)
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| Co-Investigator(Kenkyū-buntansha) |
WATAUCHI Satoshi Yamanashi Univ., Faculty of Engineering, Research Associate, 工学部, 助手 (30293442)
NAKAYAMA Yoshihiro Yamanashi Univ., Faculty of Engineering, Associate Professor, 工学部, 助教授 (40227971)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥10,900,000 (Direct Cost: ¥10,900,000)
Fiscal Year 2001: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 2000: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1999: ¥7,100,000 (Direct Cost: ¥7,100,000)
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| Keywords | functional harmonic oxides / liouidphase etiitaxv / crystal growth / single crystalline films / high temperature superconductor / intrinsic Josenhson effect / twined domain structure / detwinnine / 高温超電導体 / 結晶育成 |
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| Research Abstract |
n this study, single crystals of functional harmonic oxides, which are single-crystalline films of antimagnetic superconductor La2.KSr,Cu04 on the substrate of antiferroamgnetic semiconductor La_2CuO_4, were prepared by liquid phase epitaxial (LPE) method, and then new functions in their single crystals were discovered. The research results were summarized as follows :
(1) A new LPE technique using an infrared heating furnace, IR-LPE, was developed, and by this technique a-axis orientated singleTcrystalline films of La_<2-x>Sr_xCuO_4 with the thickness of 10 〜 250 um were grown successfully on the substrate of Zn-substituted La_2CuO_4.
(2) A new detwinning technique of La_<2-x>Sr_xCuO_4 crystals, which was named thermal difference method, was developed, since the twined domain structure in La_<3-x>Sr_xCuO_4 crystals lowers the device properties. This method is a simple, where the oxygen-annealed crystals of thickness less than 0.8 mm were fixed on the aluminum plate using epoxy glue and
… More
then cooled down. The Meissner fraction in the sample increased up to about 90 % by this method, and this result suggests that the pinning centers of the twined domain structure were almost removed.
(3) Superconducting single-crystalline layer of oxygen-excess La_2CuO_<4+8> was prepared in (Be surface of bulk single crystal of stoichiometric La_2CuO_4 by oxidization using KMnO_4 aqueous solution. It was found that the excess oxygen introduced to not only the surface part but also the center part of the bulk crystals, and that the excess oxygen penetrates into the La_2CuO_4 bulk crystal parallel to the CuO_2 planes easier than perpendicular to the CuO_2 planes.
(4) The superconducting properties of the single-crystalline films of La_<1-x>Sr_xCuO_4 depended on the film thickness, and were superior for the film thickness less than 80 urn. The intrinsic Josephson effects were observed successfully in the single-crystalline films of La_<1-x>Sr_xCuO_4 by processing toabridge-shapeof1 x 6 x 15 μm^3. Less
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