STERIC VARIATION OF THE CERIUM VALENCE IN CE2FE14B AND RELATED-COMPOUNDS

被引：88
作者：
CAPEHART, TW
MISHRA, RK
MEISNER, GP
FUERST, CD
HERBST, JF
机构：
[1] Physics Department, General Motors North American Operations Research and Development Center, Warren, MI 48090-9055
来源：
APPLIED PHYSICS LETTERS | 1993年 / 63卷 / 26期
关键词：
D O I：
10.1063/1.110075
中图分类号：
O59 [应用物理学];
学科分类号：
摘要：
Through measurements of the near-edge Ce L3 x-ray absorption structure we have investigated the influence of site volume on the cerium valence in Ce2Fe14B, Ce2Fe14BHx, and Ce2Fe17. The crystal structures of these compounds are isomorphic with those of technologically important permanent magnet materials. Confirming other experiments, we find that the Ce ion in Ce2Fe14B is in a strongly mixed-valent alpha-like state which is incompatible with a local 4f moment. Comparison of the spectroscopically determined valences of the three materials demonstrates a shift toward a gamma-like cerium state, which supports a magnetic moment, as the steric volume of the Ce site(s) increases. Our results strongly suggest that the volume of the rare-earth site is the principal factor controlling the Ce chemical valence in these systems.
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页码：3642 / 3644
页数：3
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