Ab initio study of electronic structure and magnetic properties of MFe3N (M = Ru and Os)

Ab initio study of structural, thermodynamic, elastic, mechanical, magnetic and electronic properties of the cubic perovskite MFe3N (M = Ru and Os) has been reported using the FP-LMTO method within the gradient generalized approximation for the exchange and correlation potential. The calculations were performed at several lattice parameters to obtain the MFe3N equilibrium volume. The magnetic phase stability was determined from the total energy calculations for both the nonmagnetic (NM) and ferromagnetic (FM) phases. These theoretical calculations clearly indicate that both at ambient and high pressures, the ferromagnetic phase is more stable than the nonmagnetic phase. In equilibrium volume, the LMTO calculations have shown that the magnetic moments increase in the sequence RuFe3N > OsFe3N. Our band structure calculations show that MFe3N (M = Ru and Os) compounds possess metallic character. The thermodynamic properties such as heat capacity and Debye temperatures are calculated with pressure and temperature are successfully obtained. The elastic constants at equilibrium are also determined. We derived the bulk and shear moduli, Young’s modulus, and Poisson’s ratio. The Debye temperature of MFe3N was estimated from the average sound velocity.