First-principles study on formation mechanism of Nd-O for high coercivity magnets
Project/Area Number |
23560826
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Structural/Functional materials
|
Research Institution | Tohoku University |
Principal Investigator |
CHEN Ying 東北大学, 工学(系)研究科(研究院), 教授 (40372403)
|
Project Period (FY) |
2011-04-28 – 2015-03-31
|
Project Status |
Completed (Fiscal Year 2014)
|
Budget Amount *help |
¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000)
Fiscal Year 2013: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2012: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
Fiscal Year 2011: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
|
Keywords | 希土類磁石 / Nd-O / 粒界構造 / 生成機構 / 第一原理計算 / Cu / 高保磁力 |
Outline of Final Research Achievements |
To have a thorough understanding on the formation mechanism of disordered fcc-NdOx phase formed at the interface of Nd/Nd-Fe-B, and its relation to the surface coercivity, ground state analysis for whole oxygen concentration in Nd-O has been performed by combing the LSDA+U and the Cluster Expansion Method (CEM). Systematic calculations revealed that a sequent fcc-based structures formed by introducing oxygen vacancies into NdO is stable in almost all 0-50% oxygen concentration range, whereas in a series hcp-based structures developed from hp5-Nd2O3 no stable structure is observed, which coincides with the experiments very well. Large scale interface calculations show that the NdOx-fcc/Nd-dhcp is more stable, further explained the relation between the phase stability and coercivity. The stability and binding properties of the Cu-doped Cu-fcc-NdOx structures which was reported to be favorite for increasing coercivity are investigated.
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Report
(4 results)
Research Products
(16 results)