磁性超晶格的静磁能和磁相图的唯像理论研究

Study of Phenomenological Theory of Magnetostatic Energy and Phase Diagram of Magnetic Superlattice

计算了包含不同自旋取向的单畴粒子具有短程交换相互作用能、各向异性能及长程偶极相互作用能的磁性超晶格的静磁能．利用能面图和局域能量极小模型得到了磁相图和磁滞回线，研究了有限尺寸和温度效应，计算结果较好地解释了在超薄磁性薄膜中观察到的两种磁相（磁化强度平行和垂直于薄膜平面）的转变行为．

The magnetostatic energies of two dimensional magnetic square lattice and sandwiches with long range dipole dipole interactions, short range exchange interactions and magnetic surface anisotropy have been calculated. Based on the energy surfaces and the located energy minimum, the phase diagrams and hysteresis are obtained. The calculated results explain well the observed transition of two magnetic phases ( perpendicular to magnetization phase and in plane magnetization phase) with varying temperature in ultrathin ferromagnetic films.