| Project/Area Number |
62065004
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| Research Category |
Grant-in-Aid for Specially Promoted Research
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| Allocation Type | Single-year Grants |
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| Research Institution | TOKAI UNIVERSITY (1988-1989)
The University of Tokyo (1987) |
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Principal Investigator |
TANAKA Shoji TOKAI UNIV., DEP. OF PHYSICS, PROFESSOR, 理学部, 教授 (50010624)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAGI Hidenori THE UNIV. OF TOKYO, DEP. APPL. PHYSICS, ASSISTANT, 工学部, 助手 (40187935)
MAEDA Atsutaka THE UNIV. OF TOKYO, DEP. APPL. PHYSICS, ASSISTANT, 工学部, 助手 (70183605)
FUJIWARA Takeo THE UNIV. OF TOKYO, DEP. APPL. PHYSICS, ASSOC. PROFESSOR, 工学部, 助教授 (90011113)
UCHIDA Shinichi THE UNIV. OF TOKYO, DEP. APPL. PHYSICS, ASSOC. PROFESSOR, 工学部, 助教授 (10114399)
UCHINOKURA Kunimitsu THE UNIV. OF TOKYO, DEP. APPL. PHYSICS, PROFESSOR, 工学部, 教授 (20015564)
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| Project Period (FY) |
1987 – 1989
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| Keywords | High-temperature superconducting oxides / Electron doping / Hole doping / Band structural calculation / t-t'-J model / Pure ozone / In-situ growth of thin films / Microwave surface impedance |
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| Research Abstract |
1) As a results of the search for new materials, several new superconducting materials (T^*-phase compounds, T' phase compounds and the one which contains both BiO layer and NdO layer) were found in this research. In particular, the so-called T' phase compounds is highly unique in the sense that the itinerant carriers are electrons different from all other cuprate superconductors.
2) Various physical properties, including magnetic properties, optical properties, transport properties were investigated systematically in almost all kinds of cuprate superconductors both for high-quality polycrystals and single crystals. In particular, similarity and dissimilarity between hole-doped and electron-doped superconductors were clarified. These results provide a key information to identify the mechanism of high-temperature superconductivity.
3) Energy bands structure were calculated for various CuO based materials.
4) The so-called t-t'-J model was investigated numerically by the exact diagonalization of the hamiltonian in finite systems. Calculations are extended not only for the ground state energies but for 2-hole binding energies, antiferromagnetic correlations etc.
5) The process for synthesizing high-quality single crystalline thin films without post annealing in oxygen atmosphere was studied. By using MBE technique coupled with oxidization by pure ozone, it became possible to synthesize high-quality superconducting thin films in in-situ conditions. These films will contribute to the experiments in various field.
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