2000 Fiscal Year Final Research Report Summary
Ab-inito Molecular Dynamics for Magnetic Materials
| Project/Area Number |
11694066
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| Research Category |
Grant-in-Aid for Scientific Research (B).
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
物性一般(含基礎論)
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| Research Institution | Kanazawa University |
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Principal Investigator |
ODA Tatsuki Kanazawa Univ., Fac.of Sci., Lecturer, 理学部, 講師 (30272941)
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| Project Period (FY) |
1999 – 2000
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| Keywords | magnetism / first-principles molecular dyamics / vector-type spin structure / noncollinear magnetic structure / magnetic excitation / transition metal cluster / magnetic fluid / magnetic correlation function |
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| Research Abstract |
In this project, the following two purposes have been studied ; (1) carring out a first-principles molecular dynamics (MD) simulation on the system with noncollinear magnetism, and (2) evaluating the magnetic excitation from the first-principles technique.
(1) The disordered magnetic system, for example, liquid or amorphous iron, has never been calculated due to lack of computer capabilities even with using the parallelized code developed. However, the first-principles MD has been carried out on the liquid oxygen which modeled by 32 magnetic molecules in the box with periodic boundary. The magnetic correlation function which represents the magnetic structure of system was for the first time evaluated from first-principles for a magnetic fluid system. Compared with the result of neutron diffraction measurement, the calculated correlation function has a qualitative agreement. With using the data of first principles MD, it is require to analyze details of structural and dynamical properties of the system.
(2) In order to evaluate the magnetic excitation, a spin constraint technique has been developed. The code developed was used in the calculations of magnon frequencies for the ferromagnetic bulk system (bcc Fe) and excitation energies for the ferromagnetic dimer. At the former case, the calculated frequencies are about half in value of results in both experiments and other calculations. The algorithm for evaluation has to be improved. At the latter case, results for the iron dimer have been summarized in a paper with including the calculation method.
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