Magnetic domain observation of hydrogenation disproportionation desorption recombination processed Nd–Fe–B powder with a high-resolution Kerr microscope using ultraviolet light
Magnetic domain observation of hydrogenation disproportionation desorption recombination processed Nd–Fe–B powder with a high-resolution Kerr microscope using ultraviolet light
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DOI：
10.1063/1.3339816
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发表时间：
2010-04
影响因子：
3.2
通讯作者：
M. Takezawa;K. Maruko;N. Tani;Y. Morimoto;J. Yamasaki;T. Nishiuchi;S. Hirosawa
中科院分区：
文献类型：
--
作者：
M. Takezawa;K. Maruko;N. Tani;Y. Morimoto;J. Yamasaki;T. Nishiuchi;S. Hirosawa
建立了一台利用紫外光进行高分辨磁畴观察的克尔显微镜，并对氢化还原脱附复合（HDDR）粉末的磁畴结构和磁化过程进行了研究。紫外克尔显微镜可以观察到纳米尺寸的畴图案。施加直流电场1.0 kOe的HDDR粉末在解吸复合（DR）的时间为12分钟产生突然的壁运动。由晶界施加的钉扎力是不够的，因为富钕相层沿沿着这些边界是不存在的DR时间为12分钟。对于HDDR粉末在DR时间大于14分钟，改变磁场高达1.0千奥斯特产生没有可观察到的壁运动。HDDR粉末的高介电常数是由于晶界处的畴壁钉扎所致。
A Kerr microscope that uses ultraviolet (UV) light for high-resolution domain observation was built, and the domain structure and magnetization process of hydrogenation disproportionation desorption recombination (HDDR) powder were examined. The UV Kerr microscope could observe nanometer-sized domain patterns. Applying a dc field of 1.0 kOe to HDDR powder at a desorption recombination (DR) time of 12 min produced abrupt wall motion. The pinning force exerted by the grain boundaries is inadequate for producing high coercivity because the Nd-rich phase layers along these boundaries are absent at a DR time of 12 min. For HDDR powder at a DR time greater than 14 min, changing the magnetic field by up to 1.0 kOe produced no observable wall motion. It follows that the high coercivity of HDDR powder is due to domain wall pinning at the grain boundaries.