不规则铁磁纳米线阵列的平均截止温度:静磁相互作用的影响

Averaged Blocking Temperatures of Nanowire Arrays:Effects of the Nanowires Magnetostatic Interactions

利用蒙特卡洛方法数值计算了不规则铁磁纳米线阵列的平均截止温度,重点考察了静磁相互作用的影响。纳米线组成三角形点阵,纳米线长度满足高斯分布。推导出非均匀纳米线间的静磁相互作用的解析表达式,在此基础上得到截止温度满足的解析方程。结果表明,纳米线长度分布宽度越大,系统的截止温度越小,即系统越不稳定。另外纳米线间的长程静磁相互作用也有利于系统的稳定。数值试验证明我们决定截止温度的方法简单精确,对纳米线长度涨落敏感,利用这种方法对系统稳定性的分析结果与前人相符。

The averaged blocking temperatures of Nanowire Arrays are calculated by Monte Carlo method with emphasis on the effects of the nanowires＇ magnetostatic interactions. The nanowires have a length fluctuation, which is described by a Gaussian distribution, and form a triangle lattice. The rnagnetostatic interaction between two nanowires with different length and radius is derived. Based on that, an analytical expression for the blocking temperature is given. Numerical results show that the broade- ning of the nanowire length distribution decreases the blocking temperature of the system, which implies that the system becomes more unstable. It also shows that our method for determining the blocking ternperature is more accurate and sensitive to the length fluctuation with comparison to other methods. The results obtained here are in good accordance with those of the references.