Stability and mechanical properties of various Hf-H phases： A density-functional theory study

We performe first-principles density functional theory calculations to investigate the stability and mechanical properties of various HfHx （0 ≤ x ≤ 1） phases. For pure Hf phases, the calculated results show that the HCP and FCC phases are mechanically stable, while the BCC phase is unstable at 0 K....

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Bibliographic Details
Published inChinese physics B Vol. 26; no. 10; pp. 326 - 330
Main Author 肖伟 孙璐 黄树晖 王建伟 程磊 王立根
Format Journal Article
LanguageEnglish
Published 01.10.2017
Subjects
BCC相
fcc相
力学性能
密度泛函理论
机械稳定性
氢原子
第一性原理计算
计算结果
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Summary:We performe first-principles density functional theory calculations to investigate the stability and mechanical properties of various HfHx （0 ≤ x ≤ 1） phases. For pure Hf phases, the calculated results show that the HCP and FCC phases are mechanically stable, while the BCC phase is unstable at 0 K. Also, as for various HfHx phases, we find that H location and concentration could have a significant effect on their stability and mechanical properties. When 0 ≤ x ≤ 0.25, the HCP phases with H at （tetrahedral） T sites are energetically most stable among various phases. The FCC and BCC phases with H at T sites turn to be relatively more favorable than the HCP phase when H concentration is higher than 0.25. Furthermore, our calculated results indicate that the H solution in Hf can largely affect their mechanical properties such as the bulk moduli （B） and shear moduli （G）.
Bibliography:Wei Xiao1,2, Lu Sun1, Shu-Hui Huang1, Jian-Wei Wang1, Lei Cheng1, Li-Gen Wang1（1 General Research Institute for Nonferrous Metals, Beijing 100088, China ; 2 University of Science and Technology Beijing, Beijing 100083, China）
first-principles, hafnium, hydrogen
11-5639/O4
We performe first-principles density functional theory calculations to investigate the stability and mechanical properties of various HfHx （0 ≤ x ≤ 1） phases. For pure Hf phases, the calculated results show that the HCP and FCC phases are mechanically stable, while the BCC phase is unstable at 0 K. Also, as for various HfHx phases, we find that H location and concentration could have a significant effect on their stability and mechanical properties. When 0 ≤ x ≤ 0.25, the HCP phases with H at （tetrahedral） T sites are energetically most stable among various phases. The FCC and BCC phases with H at T sites turn to be relatively more favorable than the HCP phase when H concentration is higher than 0.25. Furthermore, our calculated results indicate that the H solution in Hf can largely affect their mechanical properties such as the bulk moduli （B） and shear moduli （G）.
ISSN:1674-1056
2058-3834
DOI:10.1088/1674-1056/26/10/106103