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Title: Solid-solution stability and preferential site-occupancy in (R-R′){sub 2}Fe{sub 14}B compounds

Abstract

The rare-earth (R) uniaxial anisotropy of R{sub 2}Fe{sub 14}B compounds with magnetic R atoms (e.g., Nd or Pr) is at the origin of the exceptional hard magnetic properties achieved in magnets based on these compounds. The uniaxial anisotropy found in Ce{sub 2}Fe{sub 14}B is attributed mainly to the magnetism of Fe. Ce is the most abundant R element and there has been much recent effort to fabricate magnets in which Ce is partially substituted for Nd. In the present neutron study of (R{sub 1−x}Ce{sub x}){sub 2}Fe{sub 14}B (R = La or Nd), Ce is found to enter the R{sub 2}Fe{sub 14}B phase over the entire composition range. The crystallographic parameters decrease with increasing Ce content and the Ce atoms preferentially occupy the smaller 4f sites. It is concluded that Ce in these (RR′){sub 2}Fe{sub 14}B compounds essentially maintains the intermediate valence character found in Ce{sub 2}Fe{sub 14}B. It is proposed that, in this intermediate valence state, Ce weakly contributes to uniaxial anisotropy, thus making a link with the fact that significant coercivity is preserved in Ce-substituted NdFeB magnets.

Authors:
;  [1];  [2];  [1];  [2];  [3];  [4];  [5];  [1];  [2];  [6]
  1. CNRS, Inst NEEL, F-38000 Grenoble (France)
  2. (France)
  3. (Japan)
  4. Advanced Material Engineering Div., Toyota Motor Corporation, Susono 410-1193 (Japan)
  5. Institut Laue-Langevin, CS 20156-38042 Grenoble cedex 9 (France)
  6. (Brazil)
Publication Date:
OSTI Identifier:
22590796
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 108; Journal Issue: 24; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANISOTROPY; ATOMS; COERCIVE FORCE; CRYSTALLOGRAPHY; MAGNETIC PROPERTIES; MAGNETISM; MAGNETS; RARE EARTHS; SOLID SOLUTIONS; STABILITY; VALENCE

Citation Formats

Colin, C. V., Dempsey, N. M., Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble, Ito, M., Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble, Advanced Material Engineering Div., Toyota Motor Corporation, Susono 410-1193, Yano, M., Suard, E., Givord, D., Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble, and Instituto de Fisica, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro. Solid-solution stability and preferential site-occupancy in (R-R′){sub 2}Fe{sub 14}B compounds. United States: N. p., 2016. Web. doi:10.1063/1.4953874.
Colin, C. V., Dempsey, N. M., Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble, Ito, M., Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble, Advanced Material Engineering Div., Toyota Motor Corporation, Susono 410-1193, Yano, M., Suard, E., Givord, D., Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble, & Instituto de Fisica, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro. Solid-solution stability and preferential site-occupancy in (R-R′){sub 2}Fe{sub 14}B compounds. United States. doi:10.1063/1.4953874.
Colin, C. V., Dempsey, N. M., Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble, Ito, M., Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble, Advanced Material Engineering Div., Toyota Motor Corporation, Susono 410-1193, Yano, M., Suard, E., Givord, D., Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble, and Instituto de Fisica, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro. 2016. "Solid-solution stability and preferential site-occupancy in (R-R′){sub 2}Fe{sub 14}B compounds". United States. doi:10.1063/1.4953874.
@article{osti_22590796,
title = {Solid-solution stability and preferential site-occupancy in (R-R′){sub 2}Fe{sub 14}B compounds},
author = {Colin, C. V. and Dempsey, N. M. and Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble and Ito, M. and Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble and Advanced Material Engineering Div., Toyota Motor Corporation, Susono 410-1193 and Yano, M. and Suard, E. and Givord, D. and Univ. Grenoble Alpes, Inst NEEL, F-38000 Grenoble and Instituto de Fisica, Universidade Federal do Rio de Janeiro, 21941-972 Rio de Janeiro},
abstractNote = {The rare-earth (R) uniaxial anisotropy of R{sub 2}Fe{sub 14}B compounds with magnetic R atoms (e.g., Nd or Pr) is at the origin of the exceptional hard magnetic properties achieved in magnets based on these compounds. The uniaxial anisotropy found in Ce{sub 2}Fe{sub 14}B is attributed mainly to the magnetism of Fe. Ce is the most abundant R element and there has been much recent effort to fabricate magnets in which Ce is partially substituted for Nd. In the present neutron study of (R{sub 1−x}Ce{sub x}){sub 2}Fe{sub 14}B (R = La or Nd), Ce is found to enter the R{sub 2}Fe{sub 14}B phase over the entire composition range. The crystallographic parameters decrease with increasing Ce content and the Ce atoms preferentially occupy the smaller 4f sites. It is concluded that Ce in these (RR′){sub 2}Fe{sub 14}B compounds essentially maintains the intermediate valence character found in Ce{sub 2}Fe{sub 14}B. It is proposed that, in this intermediate valence state, Ce weakly contributes to uniaxial anisotropy, thus making a link with the fact that significant coercivity is preserved in Ce-substituted NdFeB magnets.},
doi = {10.1063/1.4953874},
journal = {Applied Physics Letters},
number = 24,
volume = 108,
place = {United States},
year = 2016,
month = 6
}
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