Cu_3N弹性和热力学性质的第一性原理研究

First-principles calculation of elastic and thermodynamic properties of copper nitride

利用基于密度泛函理论的第一性原理全势线性缀加平面波方法,研究了立方反ReO3结构Cu3N在零温(0K)零压下的平衡晶格常数、体弹模量及其对压强的一阶导数,计算结果与其他实验及理论结果基本相符.同时得出Cu3N的弹性常数,Poisson比等,并分析出Cu3N在零温零压下是稳定的.通过准谐Debye模型计算Cu3N的热力学性质,得到了Cu3N的晶格常数、等压比热容、等容比热容、热胀系数与温度和压强之间的关系,同时计算出不同温度不同压强下其体弹模量及Debye温度的值。

A first-principles full-potential linearized augmented plane wave（FP-LAPW） method based on the density functional theory is applied to the study of the static equilibrium lattice structure as well as the elastic constants of the cubic antiReO3 structural copper nitride（Cu3N）.The quasi-harmonic Debye model,in which the phononic effects are considered,is used to investigate the thermodynamic properties of Cu3N.The pressure and temperature dependences of lattice constant,heat capacity and thermal expansion coefficient are successfully obtained.The bulk modulus and Debye temperature are also calculated at different pressures and temperatures.