自发磁化强度

磁性薄膜自发磁化强度的变分累计展开分析

Analytical Study of Spontaneous Magnetization with Variational Cumulant Expansion in Magnetic Thin Film

结果表明：自发磁化强度依赖于薄膜的层数，在某一临界厚度以下，自发磁化强度随薄膜原子层数的减小而迅速减小。

For thicknesses below a critical thickness , the spontaneous magnetization depends on the number of atomic layers and decreases rapidly as the number of atomic layers is decreased .

利用变分累计展开方法，分析了Heisenberg磁性薄膜的自发磁化强度到三级累积展开。

The magnetic properties of quantum Heisenberg film is studied in variational cumulant expansion method .

交换交互作用，而不是自发磁化强度，明显地受制备条件的影响。

The exchange interaction , but not the spontaneous magnetisation , is strongly influenced by the preparation conditions .

因此，可以得出结论，即其一个自发磁化强度点畴是由一束晶柱或长成的晶粒组成，并都处在单畴状态。

Thus , it can be concluded , that a spontaneous magnetization dot domain is consisted of a bundle of crystalline columns or grown-up crystallites , which all are in a single domain mode .

在引进单变分参数情况下，系统的自由能，内能，比热和自发磁化强度被计算到四阶近似；在双变分参数情况下，上述物理量被计算到二阶近似。

The free energy , internal energy , specific heat and spontaneous magnetization are calculated to the 4th order approximation with the trial action of one variational parameter and to the 2nd order approximation with the trial action of two variational parameters .