铁磁颗粒膜自旋激发谱和热力学性质研究

Study on Ferromagnetic Granular Film Spin Excitation Spectrum and Thermodynamic Property

求出了铁磁颗粒膜的自旋波激发谱和自旋极化激发谱随颗粒粒径和温度的变化规律,以及膜的磁化强度、磁化率、热容量．以(α-C;H)1-xCox颗粒膜为例作具体计算．结果表明:颗粒膜的自旋波激发谱的频率随颗粒粒径增大而减小,与温度无关;而颗粒膜的自旋极化激发谱与温度有关,表现出与铁磁块状晶体自旋波谱不同的变化特征．在零级近似下,由颗粒膜自旋波激发谱引起的磁化强度、热容量随温度变化规律与块状晶体相同,而一级近似下表现出颗粒膜与块状晶体的偏离．

The authors worked out the spin excitation spectrum for ferromagnetic granular film and spinpolarized excitation spectrum with granular diameter and temperature, and magnetization, susceptibility and thermal capacity with temperature. Using the （α-C：H）1-xCox granular film as an example, the authors can see that the frequency of spin wave excitation spectrum minishes with granular diameter increasing, being independent of temperature; but spin-polarized excitation spectrum is dependent of temperature, it puts up a different property to cube ferromagnetic crystal＇s spin wave spectrum at zero-order approximation, the laws that spin wave excitation spectrum-caused magnetization, thermal capacity with temperature are homology to cube crystal＇s, but there are a departure at one-order approximation.