| Project/Area Number |
61540244
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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 | Nara Medical University |
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Principal Investigator |
AKAI Hisazumi Professor of Nara Medical University, 医学部, 助教授 (70124873)
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| Co-Investigator(Kenkyū-buntansha) |
JO Takeo Professor of Osaka University, 理学部, 講師 (20093487)
HIRAI Kunitomo Professor of Nara Medical University, 医学部, 講師 (60156627)
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| Project Period (FY) |
1986 – 1987
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| Project Status |
Completed (Fiscal Year 1987)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1987: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1986: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | transition metal alloy / lattice distortion / multiple spin-density-wave / martensitic transformation / disordered alloy / KKR-CPA method / 電子構造 / スレータ・ポーリング曲線 / 電子状態 / スレーターポーリング曲線 |
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| Research Abstract |
The main purpose of the present project is to study the relation between the electronic structure and the lattice of transition metals and alloys. Several different approaches have been tried: 1. Electronic structure of transition metal alloy are investigated by use of the KKR-CPA method to study the microscopic origin of the martensitic transformation which often is observed for these alloys. The following results are obtained: (1) By calculating the response of the lattice to the external force, it is shown that an fcc-fct instability is expected for FePd. (2) The present first-principle calculation well reproduces the so-called Slater-Pauling curve of magnetic moment of 3d allyoys. (3) The lattice constants of these alloys are determined by minimizing the total energy: a magnetic and a chemical contributions to the cohesive properties are investigated.
2. The electronic structure of Mn in the multiple spindensity-wave (MSDW) state is investigated by the tight-binding model. The relation between the number of d electrons and the MSDW state is discussed and the concentration dependence of the MSDW state of MnFe alloys are explained by taking account of the tetragonal distortion. Also to discuss such complicated systems from the first-principle, LMTO computer code is developed. As a typical example the lattice constant of the antiferromagnetic Mn is performed: the calculation of the MSDW state as well as the tetragonally distorted systems are now in progress.
3. The lattice distrotion which is compatible with the possible magnetic structure is discussed by use of the Landau's expansion of free energy and the phase diagram in the plane spanned by temperature and composition is constructed. Phase diagrams which appear for Mn alloys are explained systematically by taking account of the coupling between three independnt spin-density-waves and the lattice distortion. Also explained is the two tetragonal phases appearing in CsCl-type AuMn.
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