六角相ErAx (A=H,He)体系弹性性质的第一性原理研究

本文采用第一性原理研究了六角相ErA_x (A=H, He)的弹性性质, 其中x=0, 0.0313, 0.125, 0.25, 分别讨论了体系中不同浓度的氢和氦对体系弹性性质的影响. 计算结果表明, 六角相铒-氢体系晶体的弹性常数、体弹模量、剪切模量、杨氏模量基本上随着晶体中氢的浓度增加而增加, 然而, 铒-氦体系的弹性常数、体弹模量、剪切模量和杨氏模量几乎随着氦浓度的增加而降低. 从电荷转移方面分析了氢和氦与Er的相互作用, 发现六角相ErH_x的弹性性质随H浓度的变化机理与ErHe_x随He浓度的变化机理不同. 关键词： 第一性原理 弹性性质 x')" href="#">六角相ErH_x x')" href="#">六角相ErHe_x

First-principles study on elastic properties of hexagonal phase ErAx (A=H,He)

The elastic properties of hexagonal phase ErA_x (A=H, He) have been calculated by the first-principles method, where x=0, 0.0313, 0.125, 0.25. Effects of different concentrations of hydrogen and helium on the elastic properties of ErA_x systems have been investigated in detail. Results show that the elastic constants, Young's modulus, bulk modulus and shear modulus of ErH_x systems increase mainly with increasing hydrogen concentration, whereas, those elastic properties of ErHe_x systems almost decrease with increasing helium concentration. We have investigated the changes in the charge densities of Er atoms produced by A atoms. It was found that the mechanism for the change of the elastic properties of hexagonal phase ErH_x with increasing hydrogen atoms is different from that of ErHe_x with increasing helium atoms.
Keywords： first-principles elastic properties x')" href="#">hexagonal phase ErH_x x')" href="#">hexagonal phase ErHe_x