Structural stability and magnetism of FeN from first principles

In the framework of density functional theory (DFT), the structural and magnetic properties of FeN mono nitride have been investigated using the all electrons augmented spherical wave method (ASW) with a generalized gradient GGA functional for treating the effects of exchange and correlation. Calculation of the energy versus volume in hypothetic rocksalt (RS), zinc-blende (ZB) and wurtzite (W) types structures shows that the RS-type structure is more stable than the others. Spin polarized calculation results at equilibrium volume indicate that the ground state of RS-FeN is ferromagnetic with a high moment, while ZB-FeN and W-FeN are non magnetic. The influence of distortions on the stability is taken into account by considering FeN in two different face-centred tetragonal structures (fct): fct-rocksalt and fct-zincblende. The magnetovolume effects with respect to Slater-Pauling-Friedel model are discussed. The electronic structures analyzed from site and spin projected density of states are reported. A discussion of the structural and magnetic properties of FeN is given with respect to N local environment of Fe.