| Project/Area Number |
24360261
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Partial Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Physical properties of metals
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| Research Institution | Tohoku University |
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Principal Investigator |
KITAKAMI Osamu 東北大学, 多元物質科学研究所, 教授 (70250834)
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| Co-Investigator(Kenkyū-buntansha) |
OKAMOTO Satoshi 東北大学, 多元物質科学研究所, 准教授 (10292278)
KIKUCHI Nobuaki 東北大学, 多元物質科学研究所, 助教 (80436170)
SHIMATSU Takehito 東北大学, 学際科学国際高等研究センター, 教授 (50206182)
YANAGIHARA Mihiro 東北大学, 多元物質科学研究所, 教授 (40174552)
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Project Status |
Completed (Fiscal Year 2014)
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| Budget Amount *help |
¥16,120,000 (Direct Cost: ¥12,400,000、Indirect Cost: ¥3,720,000)
Fiscal Year 2014: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000)
Fiscal Year 2013: ¥3,770,000 (Direct Cost: ¥2,900,000、Indirect Cost: ¥870,000)
Fiscal Year 2012: ¥8,450,000 (Direct Cost: ¥6,500,000、Indirect Cost: ¥1,950,000)
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| Keywords | 永久磁石 / NdFeB / 保磁力 / 微細加工 / パルス磁場 / 反転ダイナミクス / ナノサイズ / 反転磁区 / ナノコンポジット / 単一粒子 / 磁化反転 / 磁化挙動 |
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| Outline of Final Research Achievements |
The aim of this study is to elucidate the magnetization dynamics of single NdFeB dot. By combining our highly sensitive Hall effect magnetometry with the newly developed large amplitude ns pulse field generator, we have traced magnetization reversal process in single dot after application of slowly varying dc fields and ns pulse fields. Nucleation of reversed domains of about 100 nm in diameter takes place at same points for both cases, but the significant difference is observed in their following expansion. In the dc field case, neighboring nucleated domains are linked to each other, resulting in a maze-like domain structure, while nucleated domains tend to expand isotropically in the pulse field case. Such difference depending on application fields can be explained by assuming multiple energy barriers for magnetization reversal. This result leads us to believe that elimination of defects or something which lower the energy barrier contributes to the enhancement of coercivity.
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