Fe9Si的电子结构及铁磁性质的第一性原理研究
First Principles Study on Electronic Structure and Ferromagnetic Properties of Fe9Si

采用第一性原理的密度泛函理论（Density Functional Theory）赝势平面波方法， 对Fe9Si的电子结构和铁磁性质进行理论计算。 计算结果表明： (1) Fe9Si具有负的形成热-0.1094 eV/atom， 结合能5.124 eV/atom， 表明Fe9Si合金具有强结合力和结构稳定性； (2) Fe9Si具有典型的金属能带特征， 穿过Fermi能级的能带最主要是Fe的3d态电子的贡献， 其次是来自Si的3p态电子的贡献。 结合键不是单一金属键， 而是金属键和共价键组成的混合键； (3) Fe9Si的铁磁性主要来自Fe原子的未满层壳的3d态电子的自旋。 计算结果为Fe9Si铁磁性材料的设计与应用提供了理论依据。
The electronic structure and ferromagnetic properties of Fe9Si have been investigated by the first principle plane-wave pseudo-potential on the density function theory. The calculated heat of formation and cohesive energy indicate that Fe9Si intermetallic compounds have the strong alloying ability and high structural stability. The calculations of band structure and density of states(DOS) show that Fe9Si has characteristics of metal, whose bonding modes are covalence bond and metallic bond. The band through Fermi level is mainly due to the Fe 3d state and the Si 3p state. The ferromagnetic properties of Fe9Si are attributed to the 3d states of the Fe atoms. The results offer theoretical data for the design and application of the ferromagnetic material Fe9Si.