Nd2Fe14B/α″-Fe16N2双层膜磁性能和磁化反转过程的研究

摘要

In this paper, the hysteresis loops, magnetic reversal process, coercivities and energy products for Nd2Fe14B/α″-Fe16N2 bilayers are studied systematically by a three-dimensional(3D) model.It is found that the squareness of the hysteresis loop weakens with the increase of soft layer thickness (Ls).Simultaneously, the nucleation fields and coercivities decrease monotonically as the Ls increases.In addition, the calculated magnetic orientations within the film plane exhibit a process of vortex formation and annihilation.Through the calculation of the energy in the magnetization reversal process, it is found that the formation of vortex is an energy reduction process.The remanence and maximum energy products firstly enhance and decrease later with the increase of the Ls, but the coercivities decrease monotonically.The maximum value of the maximum energy products for Nd2Fe14B/α″-Fe16N2 bilayer films is 81.7 MGOe.%本文运用三维微磁学方法对Nd2Fe14B/α″-Fe16N2磁性双层膜模型垂直取向的磁滞回线、磁化反转过程、矫顽力和磁能积等进行了系统的研究.计算结果表明磁滞回线的方形度随着软磁层厚度(Ls)的增加而变差.同时,成核场和矫顽力随Ls的增加而单调递减.另外,在磁化反转的过程中发现了磁涡流态的产生和湮灭,而且进一步计算磁化反转过程中的能量变化过程发现涡流态的形成总伴随着能量的减小.剩磁和最大磁能积随Ls的增大先增大,达到峰值后迅速降低,而矫顽力呈单调递减趋势.当Ls=1 nm时,最大磁能积达到最大值81.7 MGOe.