1994 Fiscal Year Final Research Report Summary
A STUDY OF SUPERPARAMAGNETIC RESONANCE IN ULTRAFINE FERROMAGNETIC PARTICLES.
| Project/Area Number |
05640407
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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Ⅱ(磁性・金属・低温)
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| Research Institution | TOKYO INSTITUTE OF TECHNOLOGY |
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Principal Investigator |
NAGATA Kazukiyo TOKYO INSTITUTE OF TECHNOLOGY,FACUTY OF SCIENCE,PROFESSOR, 理学部, 教授 (00013491)
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| Co-Investigator(Kenkyū-buntansha) |
KATO Teruya TOKYO INSTITUTE OF TECHNOLOGY,FACUTY OF SCIENCE,ASSOCIATE, 理学部, 助手 (00224519)
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| Project Period (FY) |
1993 – 1994
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| Keywords | ULTRAFINE PARTICLES / SUPERPARAMAMAGNETISM / SPIN DYNAMICS |
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| Research Abstract |
The electron magnetic resonance of ultrafine ferromagnetic particles is a new type of of resonance unlike the ferromagnetic or paramagnetic one. We called it 'superparamagnetic resonance'. In this project the elctron spin resonances (ESR) in two different types of ultrafine particle-systems have been studied both experimentally and theoretically.
First we developed a phenomenological theory of the superparamagnetic resonance. This theroty turned out to well reproduce the results of ESR observed for the MnZn-ferrite particles dispersed in the frozen kerosene, which is a typical superparamagnetic system.
We have also studied the magnetic resonance in oxide glasses containing magnetite clusters (ultrafine particles). For this system the interactions between clusters and glassy intermediate through the surfaces of magnetite fine particles play an important role in spin dynamics. Thus we have developed the magnetic resonance theory including such interactions. The theory have been proved to describe the experimental results in random magnetic systems (e.g.spin glass syutems) as well as the present oxide system.
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