First Principles Study on the Thermodynamic Properties, Elastic Properties and Electronic Structure of Li-Doped Mg2Si

Abstract

The topic of this study is the thermodynamic properties, elastic properties and electronic structure of Mg2Si and Li-doped Mg2Si (Mg7Si4Li, Mg8Si3Li and Mg8Si4Li) by first principles based on density functional theory method. The analysis of lattice constants manifests that When Li is doped in Mg2Si, structure cell will generate lattice distortion, which can change lattice constants and total volumes. All the studied compounds are stable. However, the structure will be not as stable as Mg2Si, when Li is doped in. Intrinsic Mg2Si, exhibit the best stiffness and the strongest brittleness. Li-doped Mg2Si, can refine the brittleness but reduce the stiffness. Density of State, band structure, Mulliken electrons and electron density difference show that electrical conductivity is enhanced after Li doping in Mg2Si. Specially, Mg8Si3Li exhibits a worst stability and stiffness, a best plasticity and electroconductibility.