γ'-Fe_4N的结构和热力学性质的第一性原理计算

First-principles Calculations for Structures and Thermodynamic Properties of γ'-Fe_4N Compound

采用基于平面波模守恒赝势密度泛函理论的第一性原理方法研究了γ'-Fe_4N的结构,获得了其零温零压下的晶格常数、常温下的体弹模量以及弹性常数等基本性质参数,其计算结果与其他理论计算结果和实验值符合较好。同时应用准谐德拜模型,成功获得γ'-Fe_4N的相对体积、相对晶格常数、体弹模量、热膨胀系数以及热容随着温度、压强的变化关系。

An investigation on the structures and thermodynamic properties of γ＇-Fe4N is conducted using first-principles plane-wave norm-conserving pseudopotential method of density functional theory. The results show that the calculated lattice parameters,bulk modulus,and the elastic constants are good agreement with the experimental data and data calculated by others. Through the quasi-harmonic Debye model,the relative lattice parameters,relative volume,the bulk modulus,thermal expansion,and heat capacity under different temperatures and pressures are also successfully obtained.