Evolution of interaction domains in textured fine-grained Nd2Fe14B magnets
Evolution of interaction domains in textured fine-grained Nd2Fe14B magnets
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DOI：
10.1063/1.2751092
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发表时间：
2007-07-15
影响因子：
3.2
通讯作者：
Schultz, L.
中科院分区：
文献类型：
--
作者：
Khlopkov, K.;Gutfleisch, O.;Schultz, L.
本文用磁力显微镜系统地研究了热机械加工（模具镦粗）的不同织构度的快淬NdFeB磁体在热退磁和直流退磁状态下的磁显微结构。在热退磁状态下的热压前体中已经清楚地观察到在200和400 nm之间的尺度上具有精细对比度的各向同性磁性微结构。在具有最大织构度的磁体中，已经发现了在许多单个晶粒上具有横向扩展的广泛和明显的相互作用域。该磁体的晶体学织构已通过使用高分辨率扫描电子显微镜的电子背散射衍射进行了分析。在介观尺度上，大部分的微晶具有小于10度的取向差，宏观上产生高的剩磁值（1.34 T）。已经确定了依赖于纹理程度上的相互作用域的大小的阈值的存在。单个微晶的排列强烈影响相互作用域的形成和大小。
The magnetic microstructure of thermomechanically processed (die-upset) melt-spun NdFeB magnets with different degrees of texture in thermally demagnetized and in dc-demagnetized states has been investigated systematically using magnetic force microscopy. An isotropic magnetic microstructure with a fine contrast on a scale between 200 and 400 nm has been clearly observed in the hot-pressed precursor in the thermally demagnetized state. Broad and well-pronounced interaction domains with lateral expansion over many individual grains have been found in the magnet with a maximum degree of texture. The crystallographic texture of this magnet has been analyzed by electron backscatter diffraction using a high-resolution scanning electron microscope. On a mesoscopic scale, most of the crystallites have a misorientation smaller than 10 deg, yielding macroscopically a high value of remanent magnetization (1.34 T). The presence of a threshold value in dependence of the size of the interaction domains on the degree of texture has been identified. The alignment of individual crystallites strongly influences the formation and the size of interaction domains.