磁性超晶格中静磁波的表面退磁效应  

Effects of Surface Demagnetizing Field for Magnetostatic Waves in Magnetic Superlattices

作　　者：王选章[1] 刘凤丽[2] 牛丽[2] 

机构地区：[1]中国科学院长春光机与物理研究所,长春130032 [2]哈尔滨师范大学

出　　处：《东北林业大学学报》2003年第4期33-35,共3页Journal of Northeast Forestry University

基　　金：黑龙江省自然科学基金;教育部"首届高校骨干教师资助计划"资助

摘　　要：利用等效介质理论 ,在考虑磁性层表面动力学退磁场影响的前提下 ,首先给出了动力学磁化率 ,然后求出了色散方程。当坐标系的y轴垂直于层间界面 ,饱和磁化和外场均沿z轴方向时 ,数值计算结果表明 :表面静磁波可以在任意磁性层的相对厚度时存在 ,同时表面波的传播方向处在x -z平面的第三和第四象限中。这两结论与以往的结果不同。With the effective-medium theory, we investigate magnetostatic waves of magnetic superlattices with considering surface demagnetizing fields. The alternating magnetic susceptibility is derived for magnetic layers in the superlattices, and then the dispersion relations are obtained for the magnetostatic waves. If we take such a coordinate system in which the y axis is pointed along the interface normal, and the external field and saturated magnetization are parallel to the z axis in the x-z plane parallel to the interfaces, the numerical results show that the surface modes can exist for any values of magnetic fraction, and their wave vector is pointed to the -x side in the x-z plane. These two conclusions are completely different to those obtained in the previous works without considering the surface demagnetizing field. In addition, the shape of the bulk continuum is different, and this continuum is above the surface mode in the frequency region.

关 键 词：磁性超晶格 静磁波 表面退磁效应 等效介质理论 动力学 磁化率 

分 类 号：O482.5[理学—固体物理]