空位对Hf-Ta-C体系的结构、力学性质及电子性质影响的第一性原理研究  

Vacancy on Structures, Mechanical and Electronic Properties of Ternary Hf-Ta-C System: a First-principles Study

作　　者：彭军辉 TIKHONOV Evgenii PENG Junhui;TIKHONOV Evgenii(International Center for Materials Discovery,School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China;Department of Materials Engineering,Taiyuan Institute of Technology,Taiyuan 030008,China)

机构地区：[1]西北工业大学材料学院,材料发现国际中心,西安710072 [2]太原工业学院材料工程系,太原030008

出　　处：《无机材料学报》2022年第1期51-57,共7页Journal of Inorganic Materials

基　　金：外国人才引进与学术交流项目(B08040)。

摘　　要：本研究理论预测了三元Hf-Ta-C空位有序结构以及空位对力学性质的影响。采用第一性原理进化晶体结构预测软件USPEX,预测得到了5种热力学稳定和3种亚稳的(Hf,Ta)C_(1-x)空位有序结构,这些结构都属于岩盐结构。采用第一性原理方法,计算了(Hf,Ta)C_(1-x)空位有序结构的力学性质,并分析了力学性质随空位浓度的变化。(Hf,Ta)C_(1-x)都具有较高的体模量、剪切模量、杨氏模量和维氏硬度;各(Hf,Ta)C_(1-x)的Hf/Ta比相同时,其模量、硬度等随空位浓度增大而减小。最后,计算了(Hf,Ta)C_(1-x)的电子态密度,发现其均具有强共价性和弱金属性。本研究结果对于了解Hf-Ta-C体系的空位结构及其力学性质和应用,具有重要参考价值。In this study,the first-principles method was used to predict the vacancy ordered structures of ternary Hf-Ta-C system and the effect of vacancy on its mechanical properties.Crystal structure of(Hf,Ta)C_(1-x) under ambient pressure were predicted by first-principles evolutionary using USPEX software.This calculation found 5 stable and 3 metastable vacancy ordered structures which all share the rock-salt structure.Then,mechanical properties of(Hf,Ta)C_(1-x) vacancy ordered structures were calculated by the first-principles method,and change of mechanical properties with the concentration of vacancy was analyzed.They all showed high bulk modulus,shear modulus,elastic modulus,and Vickers hardness.Their moduli and hardness decreased with the increase of the concentration of vacancy at the same Hf/Ta ratio.Finally,their electronic density of states are calculated,revealing that their chemical bonding is a mixture of strong covalence and weak metallic.Data from this study are promising for understanding vacancy ordered structures,mechanical properties and applications of Hf-Ta-C system.

关 键 词：Hf-Ta-C体系 空位有序结构 维氏硬度 第一性原理方法 

分 类 号：O411[理学—理论物理]