具有最近邻和次近邻相互作用的亚铁磁体中的自旋波

本文在无规相近似下，利用格林函数方法，研究了具有最近邻和次近邻相互作用的亚铁磁体中的自旋波。同时还计算了在有限温度下〈Ｓｚ〉随温度的变化趋势。结果表明ＮａＣｌ和ＣｓＣｌ结构亚铁磁体中的自旋波谱及Ｚ方向上的平均自旋与只考虑最近邻相互作用的亚铁磁体有很大的差别．其根源在于次近邻相互作用的引入造成了每个自旋的关联范围和强度的增加。

Spin Waves of Ferrimagnets with Nearest-Neighbor and Next-Nearest-Neighbor Interactions

Following the random-phase-approximation, Green's function is applied to study the spin waves of ferimagnets with nearest-neighbor and next-nearest-neighbor exchange interactions. At the same time the temperature dependance of (Sz) is calculated. The results indicate that for both NaCl and CsCl structure ferrimagnets the results of spin wave spectra and mean values of spin vector in Z-direction are strongly different from that of the ferrimagnets with the nearest-neighbor interactions only. The reason is that the introduction of the next-nearest-neighbor interaction makes the extension and the strength of correlation of each spin increase.