Fe0．875Mn0．125Si2的几何结构与电子结构的第一性原理研究

First principle study on geometric structure and electronic structure of Fe0.875Mn0.125Si2

采用基于密度泛函理论的赝势平面波方法，对掺Mn的β-Fesi2的几何结构和电子结构进行了计算。计算表明：（1）杂质的掺入改变了晶胞体积及原子位置，掺杂是调制材料电子结构的有效方式；（2）在β-FeSi2中掺入杂质时掺杂原子的置换位置具有择位性，Mn掺杂时倾向于置换FeI位的Fe原子；（3）能带结构计算表明：掺Mn使得β-FeSi2的费米面向价带移动，形成了P型半导体。

The geometrical and electronic structure of Mn-doped β-FeSi2 are studied by using the first principle plane-wave pseudo-potential based on the density function theory. The geometrical structure calculation indicates that the volume of β-FeSi2 cell and the atom position change with impurity of Mn. The total energy calculations for substitution of dopant at the FeI and the FeⅡ sites reveal that Mn prefers the FeI site. The electronic structure calculation indicates that the fermi energy moves to the valences bands with impurity of Mn and become p-type semiconductor.