钴硅化合物的理论电子能量损失谱

Theoretical electron energy loss spectroscopy of cobalt silicides

本文采用扩展平面波加局域轨道方法和广义梯度近似对钴硅系中Co2Si,CoSi和CoSi2三种不同硅化物的电子结构以及电子能量损失近边结构(ELNES)进行了理论计算。结果表明计算得到的硅化物中Co的ELNES很好反映了Co在费米能级以上d的未占据态密度分布,其中Co2Si和CoSi2具有金属性质;而CoSi呈现出半金属性质。计算还表明电子能量损失谱仪应具有足够高的能量分辨率(0.2 eV),电子能量损失近边结构才能正确反映出钴硅化合物的电子结构特征。

The method of augmented plane waves plus local orhitals with the generalized gradient approximation has been performed to calculate the electronic structure and electron energy loss near edge structure （ELNES） of Co2Si,CoSi and CoSi2 cobalt silicides. The results show that the calculated ELNES directly reflect the d unoccupied states above Fermi level of cobalt in cobalt silicides. Co2 Si and CoSi2 were shown to be of metallic property; while CoSi semi-metallic. It was also shown that only when the energy resolution of the spectrometer is high enough （0.2 eV）, ELNES can accurately reflect the electronic structure of cobalt silicides.