| Project/Area Number |
01420005
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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 | TOHOKU UNIVERSITY |
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Principal Investigator |
ENDOH Yasuo Tohoku Univ., Science,Professor, 理学部, 教授 (00013483)
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| Co-Investigator(Kenkyū-buntansha) |
KAKURAI Kazuhisa Tohoku Univ., Science,Physicist, 理学部, 助手 (00204339)
YAMADA Kazuyoshi Tohoku Univ., Science,Physicist, 理学部, 助手 (70133923)
KASAYA Mitsuo Tohoku Univ.,Science,Associate Professor, 理学部, 助教授 (20004351)
KOHGI Masafumi Tohoku Univ.,Science,Associate Professor, 理学部, 助教授 (30004451)
KOMATSUBARA Tekemi Tohoku Univ.,Science,Professor, 理学部, 教授 (80004331)
鈴木 孝 東北大学, 理学部, 助教授 (30004344)
高木 滋 東北大学, 理学部, 助手 (20154750)
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| Project Period (FY) |
1989 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥32,000,000 (Direct Cost: ¥32,000,000)
Fiscal Year 1991: ¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1990: ¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1989: ¥27,000,000 (Direct Cost: ¥27,000,000)
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| Keywords | High temperature superconductivity / Magnetic correlations / Spin fluctuations / Cuprite oxides / Carrier / Strong electron correlations / Actinide compound / Crystal structure / La_<2ーx>Sr_xCuO_4 / (Pr,Nd)_<2ーx>Ce_xCuO_4 / キャリア- / 結晶歪 / 強い電子相関 / 回転陰極型X線発生装置 / 4軸・単結晶回折 / 銅酸化物 / 結晶構造 / 相転移 / 物質設計 / 空間対称性 / X線回析装置 / 強力X線発生装置 / 酸化物超伝導体 / 構造相転移 / 反強磁性秩序状態 / Nd_2CuO_4 / La_2CuO_4 / La_2NiO_4 |
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| Research Abstract |
We have elucidated the crystal structure and various properties such as magnetism, electronic conductivities etc., from the isomorphous compounds of the layerd cuprite oxide. Cuprite oxides have been thoroughly investigated in order to understand the inherent relation between high temperature superconductivity and strong electron correlations. The isomorphous Ni oxides show the interesting modulation and change in both crystal structure and magnetism, which is confirmed to have an intrinsic relation to the electronic conductivity.
Main results are as follows.
1. The doping effect on antiferromagnetism differs in two cases of either hole or electron doping. Then the strength of the doping is strongly related to the carrier orbital.
2. The quantitative relation between the carrier concentration and the spin correlation length is experimentally proved.
3. Spin fluctuations are dominated by the appearance of superconductivity.
4. Actinide compounds which are common to be material with the strongly correlated electrons have been investigated in our group. Then the similarities with those in cuprite oxide superconductors are now considered.
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