| Project/Area Number |
63420010
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| Research Category |
Grant-in-Aid for General Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Research Field |
固体物性
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| Research Institution | Kyoto University |
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Principal Investigator |
SHINJO Teruya Kyoto Univ. Inst. Chem. Res. Prof., 化学研究所, 教授 (70027043)
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| Co-Investigator(Kenkyū-buntansha) |
HOSOITO Nobuyoshi Kyoto Univ. Inst. Chem. Res., Ass. Rrof., 化学研究所, 助教授 (30165550)
NAKAYAMA Noriaki Kyoto Univ. Fac. Sci. Ass. Prof., 理学部, 助教授 (00164369)
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| Project Period (FY) |
1988 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥37,900,000 (Direct Cost: ¥37,900,000)
Fiscal Year 1990: ¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1989: ¥14,900,000 (Direct Cost: ¥14,900,000)
Fiscal Year 1988: ¥20,000,000 (Direct Cost: ¥20,000,000)
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| Keywords | Multilayers / Ultrathin films / Magnetism / Superconductivity / Mossbauer spectroscopy / Giant magnetoresistance / High-Tc Oxides / 巨大磁気抵抗効果 / La_2CuO_4 / メスバウア-効果 / 磁気秩序 / メスバウアー分光 |
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| Research Abstract |
The subject of this research is to study the magnetic and superconducting behaviors in artificially structured superlattices and to discover any new phenomenon as a result of their interplay. For this purpose, an experimental setup has been performed to prepare ultrathin oxide films by using the oxidation chamber connected to the ultrahigh vacuum deposition system, where ultrathin metal layers are prepared by controlling the thickness on an atomic scale. For the magnetization measurements, a sample-vibrating magnetometer was equipped.
A remarkable advance was achieved in the study of magnetic/nonmagnetic multilayers and artificially prepared ferromagnetic monolayer systems have been investigated. It has been recently found that the interlayer coupling is an interesting subject. The interaction between Fe layers through Au layer was found to change the sign at about 70 A.
A new type magnetoresistance was found in multilayers with antiparallel magnetic structure, such as Fe/Cr and Cu/Co/Cu/Ni (Fe). An antiparallel structure is realized by an interlayer antiferromagnetic coupling in the former case, and the antiparallel magnetic structure has been directly confirmed by neutron diffraction. In the latter case, the difference of coercive fields is the cause of antiparallel spin structure and therefore the MR change can be induced by very small fields. Such large MR effects are regarded to be characteristic of artificial metallic multilayers.
Transport phenomena in the direction perpendicular to the multilayered films are very attractive problems. Samples for the tunneling measurements are prepared by using the oxidation chamber.
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