高压下不同结构的Zr3N4的弹性性质的第一性原理计算

First-principles calculation on elastic properties of Zr3N4 with different structures under high pressure

用基于平面波赝势密度泛函理论的第一性原理方法研究了高压下空间群为I4-3D,Pna21和Pnam的三种结构的Zr3N4的弹性性质,获得了这三种物质在高压下的体弹模量B,剪切模量G,杨氏模量E,泊松比,B/G等力学性质.结果表明,在高压下这三种结构的Zr3N4都是保持力学稳定的,且这三种结构的Zr3N4在各个方向的可压缩性是各向异性的.三种结构的Zr3N4对应的体弹模量、剪切模量和杨氏模量都是随着压强的增大而增大.其中空间群为I4-3D的Zr3N4有最好的抵抗体积压缩、变形和线性压缩的能力.泊松比和B/G的数据表明三种结构在此压强范围内均有较好的延展性,高压下空间群为Pna21和Pnam的Zr3N4延展性更好.研究结论对理论研究和实验有一定参考价值.

The elastic properties of Zr3N4 with space groups of I4-3D,Pna21 and Pnam under high pressure have been investigated using the first-principles method based on the density functional theory.Bulk modulus B,shear modulus G,Young’s modulus,Possion’s ratio and B/G of them have been studied.The results show that the three structures of Zr3N4 are stable under high pressure.The compressibility of them in all directions is anisotropic.Bulk modulus,shear modulus and Young’s modulus of them increased with increasing pressure.Zr3N4 with space groups of I4-3D has the best ability to resist volume compression,deformation and linear compression.The data of Poisson’s ratio and B/G show that all of them have good ductility under this pressure range.Zr3N4 with space groups of Pna21 and Pnam are better.It has some reference value for theoretical research and experiment.