物理学报2011，Vol.60Issue(8)：578-588,11.
第一性原理研究Mg2Si同质异相体的结构、电子结构和弹性性质
First principles study of structural,electronic and elastic properties of Mg2Si polymorphs
摘要
Abstract
The structural and the elastic properties of the Mg2Si polymorphs are calculated.The calculations are performed by using the plane-wave pseudo-potential method within the framework of first principles.The anti-fluorite structure,the anti-cotunnite structure and the Ni2In-type structure of Mg2Si can retain their mechanical stability in the pressure intervals 0—7 GPa,7.5—20.2 GPa and 21.9—40 GPa,separately.The relationships between pressure and the elastic moduli （elastic constant,bulk modulus,shear modulus,Young＇s modulus,Poisson ratio and anisotropy factor） are discussed.The electron density distribution,the density of states,the bond length and the Mulliken population of these polymorphs are systemically investigated.Our results show that the anti-fluorite Mg2Si is a semiconductor and the other two polymorphs are metallic materials.The interaction between Mg 2p,3s and Si 3p plays a dominant role in the stability of the Mg2Si polymorphs.The strongest interactions in the anti-fluorite Mg2Si and the Ni2In-type Mg2Si are Mg-Mg and Mg-Si interactions,respectively.Our results are concordant with the experimental data and the previous results.关键词
态密度/电子结构/弹性常数/第一性原理Key words
density of states/electronic structure/elastic constants/first principles分类
化学化工引用本文复制引用
余本海,刘墨林,陈东..第一性原理研究Mg2Si同质异相体的结构、电子结构和弹性性质[J].物理学报,2011,60(8):578-588,11.基金项目
国家自然科学基金 （）
河南省基础与前沿技术研究计划（批准号：102300410241）资助的课题 （）
