First-principles investigation of mechanical and electronic properties of LaAg5 Laves phase under pressure
来源期刊：Journal of Rare Earths2016年第1期
论文作者：高恩强 黄福祥 陈志谦 王兰兰 张照超
文章页码：105 - 112
摘 要：The effects of applied pressure on the structural, mechanical, and electronic properties of LaAg5 compound were investigated employing the first-principles method based on the density functional theory. The mechanical results demonstrated that bulk modulus, shear modulus and Young’s modulus presented the linearly increasing dependences on the external pressure; the B/G and Poisson’s ratio indicated that La Ag5 compound was a ductile material with central forces in interatomic under pressure from 0 to 40 GPa; the universal anisotropic index was performed to investigate the elastic anisotropic of La Ag5. Additionally, the pressure dependence of the density of states and Mulliken charge were also discussed. The bonding characterization in La Ag5 was composed of metallic, covalent and ionic. The metallic component was derived from free-electron transferring from Ag-s and Ag-d to Ag-p, and from La-s to La-d. The ionic component was due to the charge movement from La to Ag. The covalent was owing to Ag-p-La-d bonding hybridization and Ag-s-Ag-p in the Ag atomic chains. The covalent and ionic bonds were stronger under pressure but there was no significant change in metallic nature.
高恩强1，黄福祥1，陈志谦2，王兰兰1，张照超1
1. College of Materials Science & Engineering Chongqing University of Technology2. Faculty of Materials and Energy Southwest University
摘 要：The effects of applied pressure on the structural, mechanical, and electronic properties of LaAg5 compound were investigated employing the first-principles method based on the density functional theory. The mechanical results demonstrated that bulk modulus, shear modulus and Young’s modulus presented the linearly increasing dependences on the external pressure; the B/G and Poisson’s ratio indicated that La Ag5 compound was a ductile material with central forces in interatomic under pressure from 0 to 40 GPa; the universal anisotropic index was performed to investigate the elastic anisotropic of La Ag5. Additionally, the pressure dependence of the density of states and Mulliken charge were also discussed. The bonding characterization in La Ag5 was composed of metallic, covalent and ionic. The metallic component was derived from free-electron transferring from Ag-s and Ag-d to Ag-p, and from La-s to La-d. The ionic component was due to the charge movement from La to Ag. The covalent was owing to Ag-p-La-d bonding hybridization and Ag-s-Ag-p in the Ag atomic chains. The covalent and ionic bonds were stronger under pressure but there was no significant change in metallic nature.
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