双层亚铁磁磁性薄膜的磁矩研究

Magnetic Moment of Double-layer Ferrimagnetic Magnetic Thin Films

采用Heisenberg模型,利用线性自旋波近似和格林函数技术研究双层亚铁磁薄膜的磁矩,分析自旋量子数、层间交换耦合、各向异性参数及温度对双层亚铁磁薄膜磁矩的影响。零温时,层内交换耦合和各向异性不影响薄膜的磁矩。低温时(温度小于等于居里温度的三分之一),当两格点的自旋量子数相等时,薄膜的磁矩不受层间交换耦合的影响,但随各向异性的增加而增加;当两格点的自旋量子数不等时,薄膜的磁矩随层间交换耦合和各向异性的增加而增加。零温时,两格点的自旋偏差(或量子波动)相等。

This paper uses Heisenberg model,Linear spin wave approximation and the Green＇s function technique to study the magnetization of double-layer ferrimagnetic thin films,analyses the effect of spin quantum number,layer exchange coupling rat,anisotropy parameter and temperature on the magnetization of the double-layer ferrimagnetic films.When the temperature is zero,interlayer exchange coupling and anisotropy parameter no affect the magnetization of double-layer ferrimagnetic films.For the low temperature,when the spin quantum numbers of two sublattices are the same,magnetization of thin film is not affected by interlayer exchange coupling,but increases with increasing anisotropy; for unequal spin quantum numbers of two sublattices,the film＇s magnetizaton increases with increasing interlayer exchange coupling and anisotropy.The spin deviations （or quantum fluctuations） of two sublattices always are the same at zero temperature.