ZrV_2结构、弹性和热力学性质的第一性原理计算  

First-principles Study of Structure, Elastic and Thermodynamic Properties of ZrV_2

作　　者：刘显坤[1] 郑洲[1] 兰晓华[1] 刘聪[1] 

机构地区：[1]中国工程物理研究院核物理与化学研究所,四川绵阳621900

出　　处：《计算物理》2013年第2期256-264,共9页Chinese Journal of Computational Physics

基　　金：国防预研项目(20100210)资助

摘　　要：采用基于密度泛函理论的第一性原理平面波赝势方法研究ZrV2的晶体结构和弹性,利用准谐Debye模型计算在不同温度(T=0～1 200 K)和不同压强(P=0～20 GPa)下ZrV2的热力学性质,包括弹性模量与压强,热熔与温度,以及热膨胀系数与温度和压力的关系.结果表明:计算的ZrV2晶格常数与实验值符合较好,晶体材料的弹性常数随着压力增加而增加;在一定温度下,相对体积、热熔随着压强的增加而减小,德拜温度、弹性模量随着压强的增加而增加,且高压下温度对ZrV2热膨胀系数的影响小于压强的影响.Structure and elastic property of ZrV2 under high pressure are investigated with first-principles calculations based on plane- wave pseudo-potetial in the framework of density functional theory within generalized gradient approximation （ GGA ）. With a quasi- harmonic Debye model, in which phonon effects are considered, we calculated thermodynamic properties of ZrV2 in a pressure range from 0 to 20 GPa and temperature range from 0 to 1 200 K. Pressure dependence of elastic constants, bulk modulus and heat capacity, and thermal expansion with pressure and temperature are presented. It shows that calculated lattice parameters of ZrV2 are in good agreement with existing experimental data and other theoretical results. Elastic constants, Debye temperature and bulk modulus increases with increasing pressure. Relative volume, heat capacity decreases with increasing pressure. Temperature effect is weaker than pressure effect in thermal expansion of ZrV2 under high pressures.

关 键 词：ZrV2 弹性 热力学性质 第一性原理 

分 类 号：O641[理学—物理化学] O649[理学—化学]