磁性镍纳米线矫顽力随角度变化规律的微磁学模拟

Micromagnetic simulation of angular dependence of coercivity of magnetic nanowires

采用微磁学模拟的方法对不同直径有限长Ni纳米线的矫顽力随角度(外磁场与纳米线长轴之间的夹角)的变化关系Hc(θ)进行了研究。结果表明:矫顽力随角度的变化规律随着纳米线直径的增大而改变;当直径小于临界直径d0(39 nm)时,纳米线矫顽力随着角度的增大而单调减小;当直径大于临界直径d0时,矫顽力随角度的变化表现出较复杂的关系,出现零角度局域极大现象以及中间某一角度的极大现象。从反磁化机制的角度对矫顽力随角度的变化规律进行了解释。

Angular dependence of the coercivity Hc（θ） of magnetic nanowires with different diameters was investigated by micromagnetic simulation, where θ is defined as the angle between the field direction and wire length）. The results show that Hc（θ） significantly depends on the nanowire diameter. For the nanowire diameter smaller than a critical diameter d0（39 nm）, the coercivity decreases as the angle increases. For the diameters larger than the critical diameter, the angular dependence of coercivity has a complicated form. There are a local maximum at zero angle and a peek at middle angle on the Hc（θ） curve. The angular dependence of coercivity is interpreted in terms of magnetization reversal mechanism.