LAUSR

Abstract The elastic, hardness, anisotropy and thermodynamic properties of h-FeN2 under pressure have been systematically investigated via the first-principles calculations. The predicted lattice constants are well consistent with the existing experimental data and the previous theoretical results. The elastic constants, polycrystalline modulus, anisotropy and hardness of h-FeN2 under pressure have been calculated. According to the obtained results, h-FeN2 is mechanically stable, possesses elastic anisotropy and high hardness, and can be classified as brittle material. In addition, the pressure and temperature dependent thermodynamic properties including the Debye temperature and isochoric heat capacity C v are also reported and discussed using the quasi-harmonic approximation (QHA). So far as we know, this is the first time quantitative study of the effects of temperature and pressure on the thermodynamic and mechanical properties of h-FeN2. Our theoretical researches still waits for experimental confirmation.