中文摘要：

目的 计算分析ζ-Fe2N和ε-Fe3N两种铁氮化合物的结构稳定性和弹性性能。方法 采用第一性原理模拟计算方法。结果 两种物相的理论晶格常数与实验值吻合较好,且两者的形成能均为负值。通过两种物相的单晶弹性常数获取了相应的多晶弹性性能,所计算体模量（B）、剪切模量（G）和杨氏模量（E）均高于实验值。ε-Fe3N多晶弹性性能的计算值与实验值存在一定的比例关系,约为1.3∶1,这个比例也适用于γ＇-Fe4N的体模量。两种物相的B/G比值分别为2.63和2.16。结论 ζ-Fe2N和ε-Fe3N具有一定的热力学稳定性。两者的剪切模量和杨氏模量接近或优于钢,且具有一定的塑性。两种物相的弹性各向异性与它们的晶体结构密切相关。

英文摘要：

The work aims to calculate and analyze structural stability and elastic properties of two kinds of iron nitrides, ζ-Fe2N and ε-Fe3N. First principles were adopted to simulate calculation method. The theoretical lattice constants of two phases coincided with well with the experimental ones, and the formation energy of two phases was negative. Corresponding polycrystal elastic properties were acquired based on monocrystal elastic constants of two phases. The calculated bulk modulus （B）, shear modulus （G） and Young＇s modulus （E） were all higher than the experimental ones. There was a certain proportional relationship between calculated and experimental values of ε-Fe3N polycrystal elastic property approximately at 1.3 ： 1, which was applicable to bulk modulus of γ-FeaN. The B/G ratio of ζ-Fe2N and ε-Fe3N was 2.63 and 2.16 respectively. ζ-Fe2N and e-Fe3N are provided with certain degree of thermodynamic stability. The shear modulus and Young＇s modulus of two phases are close to or superior to those of steel, and the B/G values indicate their ductile nature. The elastic anisotropy of two nitrides is closely related to their crystal structures.