Electronic State and Many-body Effect in Transition and Typical Element Systems
| Project/Area Number |
01540275
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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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 | Faculty of Science, Osaka University |
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Principal Investigator |
KANAMORI Junjiro Osaka Univ., Faculty of Science,, 理学部, 教授 (10028079)
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| Co-Investigator(Kenkyū-buntansha) |
AKAI Hisazumi Nara Medical University, Associate professor, 助教授 (70124873)
KIKUCHI Macoto Osaka Univ., Faculty of Science, Research associate, 理学部, 助手 (50195210)
IGARASHI Jun-ichi Osaka Univ., Faculty of Science, Research associate, 理学部, 助手 (20127179)
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| Project Period (FY) |
1989 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1990: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1989: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Ferromagnetic alloys / Typical element / Molecular Dynamics / Ni compounds / Metal-insulator transition / High T_c superconductivity / Photolectron Spectroscopy / Many body effect |
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| Research Abstract |
1. Transition metal alloys containing typical elements
A possible mechanism of enhancing the ferromagmetism of iron by introducing typical element atoms at interstitial sites is proposed. A typical element atom will modify the local electronic structure of immediately neighboring Fe atoms to convert them into pseudo-Co atoms. Then the magnetic moments of more distant Fe atoms will be enhanced in the same way as in bcc Fe-Co alloys. The mechanism seems to be operating in Fe-N systems and R-Fe-B permanent magnets. In order to substantiate it, we are preparing a band structure calculation of a regular alloy of Fe-N. We plan also to investigate the mecnism underlying the formation of an amorphous state. To that purpose a general method based on KKR for the ab initio calculation of the electronic structure of a system in which constituent atoms can take any irregular positions is proposed.
2. Compounds of transition and typical elements
By use of an rigorous diagonalization of the Hamiltonian
… More
of a finite size cluster the electronic states of Cu and Ni compounds is investigated for the following four problems. a) Role of the apical oxygen high T_C Cu oxides The spin correlation between the apical oxygen and Cu turns out to be quite small. b) The superhyperfine interaction between La nuclei and M in La_2MO_4 (M=Cu and Ni) via apical oxygens. The calculation of the internal field at La site elucidates quan-titatively the mechanism. The importance of the electron correlation is demonstrated. c) The effect of the hole itinerancy on the photoemission spectra of high T_C Cu oxides. The itinerancy as well as the electron correlation is investigated by use of a large cluster. d) The metal-insulator transition in Ni compounds The change of the ground state by changing the charge transfer energy is investigated. The antiferromagnetic insulating phase with well developed magnetic moments seems to make a transition into intermediate state with moderately large magnetic moments with small inter-atomic coupling. Less
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Report
(3 results)
Research Products
(16 results)
