SrFe_(12)O_(19)/Co纳米复合双层膜的微磁学模拟

将纳米尺寸的硬磁材料和软磁材料组成纳米复合材料是提高永磁材料磁性能和降低生产成本的重要途径。采用微磁学模拟软件OOMMF研究了软磁相厚度对SrFe_(12)O_(19)/Co纳米复合双层膜体系磁性能的影响。结果显示,固定硬磁相厚度10 nm,随着软磁相厚度(Ls)的增加,最大磁能积先增大后减小,并在Ls=13 nm时取得峰值,达到234.55 kJ/m~3,远远超过目前单相高性能SrFe_(12)O_(19)的最大磁能积40 kJ/m~3。随着软磁相厚度的增加,体系由完全耦合的单相磁反转行为转变为软磁相部分优先成核的两相反转行为,并表现出显著的剩磁增强效应,矫顽力逐渐降低。

Micromagnetic simulation of SrFe12O19/Co nanocomposite bilayer films

The nanocomposite permanent magnetic material is an important attempt to improve the magnetic properties and, at the same time, to reduce the production cost. The effect of soft magnetic phase thicknesses on the magnetic properties of SrFe12O19/Co bilayer films was studied by using micromagnetic simulation software OOMMF. The results show that when fixing the hard magnetic phase thickness as 10 nm, with the increasing of the thickness of soft phase, the maximum magnetic energy product increases first, and then decreases, and reaches the peak value 234.55 kJ/m3when Lsequals 13 nm, which is far beyond the largest energy products (40 kJ/m3) of single phase high-performance SrFe12O19. The results also show that the system changes from fully coupled single-phase reversal behavior into two-phase reversal behavior, the remanence increases, and the coercivity decreases with the increase of the thickness of soft phase (Ls).