交换耦合软/硬磁双层膜体系磁动力学性质的研究

摘要

基于Laudau-Lifshitzt 方程，在一维原子链模型的框架内研究了交换耦合软/硬磁双层膜体系的磁动力学性质，得到了软磁层在磁反转前处于一致磁结构和交换弹性磁反转过程中处于螺旋磁结构时的本征自旋波模式的频率及其空间分布特点，以及自旋波色散关系曲线。研究表明，软磁层的反磁化机制与自旋波的软模现象有密切关系，一阶自旋波模式的软化诱导了软磁层的磁反转，且磁反转的形式与一阶自旋波模式的空间分布状态相关。由磁动力学方法得到的磁反转临界场与近似的解析解得到的结果一致。%The magnetic dynamical properties of exchange-coupled soft/hard bilayer structure are investigated in the framework of a one-dimensional atomic chain model based on the Landau-Lifshitz equation.The frequencies and the spatial distribution characteristics of the spin wave eigenmodes are calculated for the uniform magnetic structure before reversal and the spiral magnetic structure during exchange-spring process.The spin wave dispersion relation was obtained.It was found that the magnetization reversal mechanism was closely related to soft mode of spin wave.The magnetization reversal of the soft layer was induced by softening of the first-order spin wave mode,and reversal process was determined by the spatial distribution of the soften mode.The critical fields determined from the magnetic properties are in good agreement with the result of analytic solution.