期刊
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
卷 401, 期 -, 页码 259-268出版社
ELSEVIER
DOI: 10.1016/j.jmmm.2015.10.042
关键词
ThMn12 structure; Magnet material; Nitrogenation; Uniaxial magnetocrystalline anisotropy
We previously reported a new compound for permanent magnets, (Nd0.7Zr0.3)(Fe0.75Co0.25)(11.5)Ti0.5N0.56, which has a high saturation polarization (J(s)) of 1.68 T and a high magnetocrystalline anisotropy field (H-a) of 2.88-4.0 MA/m. Here, we examined the effects of substituting Co and Ti at the Fe sites and Zr at the Nd sites. J(s) increased with Co substitution at the Fe sites, and higher Fe and Co content could be achieved by decreasing the Ti content to -Ti-0.5. The ThMn12 structure with high Fe and Co content (i.e. low Ti content) was stabilized mainly by -Zr-0.3 substitution at the Nd sites. The Zr substitution resolves the local mismatch in atomic size in the structure. Specifically, the atomic radius of Zr is about 88% that of Nd, so the local structure surrounding Nd (2a site) shrinks as a result of the substitution and resolves the size mismatch in the three types of local Fe six-fold symmetric hexagons in the structure. The effect of the alpha-(Fe, Co) phase on J(s) was evaluated from the phase's volume fraction measurement of 7.7% (8.1 wt%) by electron backscatter diffraction. Nitrogenation of the starting alloy also resulted in augmentation of the c-axis magnetocrystalline anisotropy. Finally, we confirmed a high J(s)(-N-1.3) of 1.71T (=1.67 T, -0.04 T for the alpha-(Fe, Co) phase) and H-a of 2.9-5.25 MA/M (H-a(-N-1.3)=525 MA/m) in the (Nd0.7Zr0.3)(Fe0.75Co0.25)(11.5)Ti0.5N alpha (alpha=0.60-1.30) compounds. (C) 2015 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据