The hcp-bcc transition of Be via anisotropy of modulus and sound velocity  

作　　者：Zhen Yang Jia-Wei Xian Xing-Yu Gao Fu-Yang Tian Hai-Feng Song 杨真;咸家伟;高兴誉;田付阳;宋海峰(Institute of Applied Physics,University of Science and Technology Beijing,Beijing 100083,China;National Laboratory of Computational Physics,Institute of Applied Physics and Computational Mathematics,Beijing 100088,China)

机构地区：[1]Institute of Applied Physics,University of Science and Technology Beijing,Beijing 100083,China [2]National Laboratory of Computational Physics,Institute of Applied Physics and Computational Mathematics,Beijing 100088,China

出　　处：《Chinese Physics B》2024年第11期361-366,共6页中国物理B（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.U23A_(2)0537,U2230401,and 52371174);Funding of National Key Laboratory of Computational Physics.

摘　　要：Based on ab initio calculations,we utilize the mean-field potential approach with the quantum modification in conjunction with stress–strain relation to investigate the elastic anisotropies and sound velocities of hcp and bcc Be under high-temperature(0–6000 K)and high-pressure(0–500 GPa)conditions.We propose a general definition of anisotropy for elastic moduli and sound velocities.Results suggest that the elastic anisotropy of Be is more significantly influenced by pressure than by temperature.The pressure-induced increase of c/a ratio makes the anisotropy of hcp Be significantly strengthen.Nevertheless,the hcp Be still exhibits smaller anisotropy than bcc Be in terms of elastic moduli and sound velocities.We suggest that measuring the anisotropy in shear sound velocity may be an approach to distinguishing the hcp–bcc phase transition under extreme conditions.

关 键 词：ANISOTROPY phase transition elastic and sound properties mean-field potential 

分 类 号：TG146.24[一般工业技术—材料科学与工程] O469[金属学及工艺—金属材料]