ホーム > 研究活動 > 2014年 > Direct observation of ferromagnetism in grain boundary phase of Nd-Fe-B sintered magnet using soft x-ray magnetic circular dichroism

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Direct observation of ferromagnetism in grain boundary phase of Nd-Fe-B sintered magnet using soft x-ray magnetic circular dichroism

Applied Physics Letters

2014年12月9日(火)

http://dx.doi.org/10.1063/1.4902329 ( T. Nakamura, A. Yasui, Y. Kotani, T. Fukagawa, T. Nishiuchi, H. Iwai, T. Akiya, T. Ohkubo, Y. Gohda, K. Hono, S. Hirosawa )

Abstract

We have investigated the magnetism of the grain boundary (GB) phase in a Nd14.0Fe79.7 Cu
0.1B6.2 sintered magnet using soft x-ray magnetic circular dichroism (XMCD) at the Fe L2,3-
edges. Soft XMCD spectra were measured from the fractured surface that was confirmed to
be covered with a thin GB phase by Auger electron spectroscopy. The magnetic moment of
Fe in the GB phase was estimated to be mGB=1.4 μB at 30 °C using the sum rule analysis for
XMCD spectra, which is 60% of that of Fe in the Nd2Fe14B compound. The temperature
dependence of mGB evaluated with reference to Fe in the Nd2Fe14B phase indicated that the
Curie temperature of the GB phase is more than 50 °C lower compared to that of Nd2Fe14B.

その他特記事項

This work has been performed with the approval of the SPring-8 Program Advisory Committee(Proposal Nos. 2010B1783, 2011A1739, 2011B1789, 2012B1016, 2013A1012, 2013B1021, 2012B1941,and 2013B1430). ESICMM (Elements Strategy Initiative Center for Magnetic Materials) is funded byMEXT. This work was in part supported by JST, CREST.


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元素戦略拠点

触媒・電池元素戦略拠点
触媒・電池元素戦略研究拠点 (京都大学)
東工大元素戦略拠点
東工大元素戦略拠点 (東京工業大学)
構造材料元素戦略研究拠点
構造材料元素戦略研究拠点 (京都大学)
高効率モーター用磁性材料技術研究組合
高効率モーター用 磁性材料技術研究組合