Elucidation and control of hydrogen re-distribusion in Fe-based magnetocaloric materials
| Project/Area Number |
18H01697
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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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| Review Section |
Basic Section 26010:Metallic material properties-related
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| Research Institution | National Institute of Advanced Industrial Science and Technology |
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Principal Investigator |
Fujita Asaya 国立研究開発法人産業技術総合研究所, 材料・化学領域, 研究チーム長 (10323073)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥17,550,000 (Direct Cost: ¥13,500,000、Indirect Cost: ¥4,050,000)
Fiscal Year 2020: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000)
Fiscal Year 2019: ¥3,640,000 (Direct Cost: ¥2,800,000、Indirect Cost: ¥840,000)
Fiscal Year 2018: ¥10,270,000 (Direct Cost: ¥7,900,000、Indirect Cost: ¥2,370,000)
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| Keywords | 磁気冷凍 / 磁気熱量効果 / 遍歴電子メタ磁性転移 / 水素 / 水素拡散 / uphill拡散 / 核生成成長 |
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| Outline of Final Research Achievements |
Hydrogen redistribution phenomenon, called the splitting phenomenon, was investigated in noble Fe-based magnetocaloric compounds. The H atoms move between the ferro- and para- magnetic states that coexist at transition temperature. By direct Magneto-optical observation, together with metallographic one at the same place, the nucleated domain boundary is pinned by the grain-boundary triple points, and this interfaces are the diffusion path of hydrogen. It was also confirmed that, by performing the first-principle calculation under careful selection of the magnetic state, the experimental results are well realized by calculations, and this means that the electronic state of hydrogen is the key factor for the splitting phenomenon.
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| Academic Significance and Societal Importance of the Research Achievements |
水素スプリット現象は、１）磁気状態に依存した、２）up-hill拡散というユニークな性質を有するが、電子論的な考察により、水素に加え、磁気状態下でのFeの電子状態を強く反映していることを明らかにした。
また、この現象は、本材料をもちいてフロンフリーな固体冷凍を実現する上で、動作点シフトによる劣化を引き起こすウイークポイントとなりえるが、本研究では、単なる磁気解析にとどまらず、材料の金属組織とのリンクを明らかにできた。このため、今後の応用に向けた材料設計にも大いに役立つ。
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Report
(4 results)
Research Products
(6 results)
