Overcoming of energy barrier for irreversible magnetization in nanocomposite magnets
Overcoming of energy barrier for irreversible magnetization in nanocomposite magnets
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DOI：
10.1016/j.jmmm.2016.08.091
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发表时间：
2017-01
影响因子：
2.7
通讯作者：
Zhu-Bai Li;Ying Zhang;B. Shen;Mingxiao Zhang;F. Hu;Jirong Sun
中科院分区：
文献类型：
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作者：
Zhu-Bai Li;Ying Zhang;B. Shen;Mingxiao Zhang;F. Hu;Jirong Sun
在纳米复合磁体中，不可逆磁化主要发生在硬质颗粒中，由于自相互作用，磁化不可逆的磁化区域中有一小部分磁化缺陷区。热激活研究表明，在Pr2Fe14B/α-Fe磁体中，由于TiNb的加入，磁体内部的缺陷区变窄。缺陷区增大了磁畴壁负向的能量密度，克服了完全硬化区的能垒。软相与硬晶外层缺陷区交换耦合，通过交换耦合促进缺陷区磁化反转。而缺陷区起到了克服势垒的阶梯作用，导致共系数的降低或多或少取决于缺陷区的宽度和各向异性。
The irreversible magnetization occurs mainly in hard grains in nanocomposite magnets, and the domain wall involves a little part of defect region in irreversible magnetization due to the self-interaction. The investigation on thermal activation shows that the defect region involved in domain wall becomes narrower due to the TiNb addition in Pr2Fe14B/α-Fe magnets. The defect region augments the energy density in the negative direction of domain wall to overcome the energy barrier of perfect hard region. The soft phase, exchange-coupled with defect region at hard grain outer-layer, promotes magnetization reversal in defect region by exchange coupling. While the defect region plays a role as a ladder to overcome the energy barrier, resulting in the decrease of coecivity more or less depending upon the width and anisotropy of defect region.