Finite element modeling of nanocomposite magnets
Finite element modeling of nanocomposite magnets
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DOI：
10.1109/20.800483
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发表时间：
1999-05
期刊：
影响因子：
--
通讯作者：
T. Schrefl;J. Fidler
中科院分区：
文献类型：
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作者：
T. Schrefl;J. Fidler
有限元建模在微磁理论框架内处理磁化过程，并考虑到磁体的复杂微观结构。吉尔伯特运动方程的数值积分提供了磁化强度的时间演化，从而显示了反向磁畴如何成核和扩展。静态微磁计算的数值结果揭示了本征磁性能对纳米复合Nd/sub 2/Fe/sub 14/B//spl α/-Fe/Fe/sub 3/B磁体剩磁和矫顽场的影响。硬相各向异性仅增加 8%，两相 Nd/sub 2/Fe/sub 14/B//spl α/-Fe 磁体的矫顽磁场就从 340 kA/m 增加到 450 kA/m。随着 Fe/sub 3/B 含量的增加，这种效应变得不那么明显。在两相Nd/sub 2/Fe/sub 14/B/Fe/sub 3/B中，软相磁化强度和/或软相交换常数的降低导致矫顽场的改善，而剩磁没有显着损失。粘合纳米复合磁体的磁性颗粒之间的静磁相互作用会稍微降低剩磁和矫顽场。
Finite element modeling treats magnetization processes within the framework of micromagnetic theory, taking into account the complex microstructure of a magnet. The numerical integration of the Gilbert equation of motion provides the time evolution of the magnetization and thus shows how reversed domains nucleate and expand. The numerical results of static micromagnetic calculations reveal the influence of the intrinsic magnetic properties on the remanence and the coercive field of nanocomposite Nd/sub 2/Fe/sub 14/B//spl alpha/-Fe/Fe/sub 3/B magnets. An increase of the hard phase anisotropy of only 8% increases the coercive field from 340 kA/m to 450 kA/m in two phase Nd/sub 2/Fe/sub 14/B//spl alpha/-Fe magnets. This effect becomes less pronounced with increasing Fe/sub 3/B content. In two phase Nd/sub 2/Fe/sub 14/B/Fe/sub 3/B, the reduction of the soft phase magnetization and/or the soft phase exchange constant leads to an improvement of the coercive field without a significant loss in remanence. The magnetostatic interactions between the magnetic particles of bonded, nanocomposite magnets slightly reduce the remanence and the coercive field.