Electronic Structure of Substitutional 3d Impurities in γ' - Fe4N

The magnetic and electronic structure of 3d localized impurities (Sc, Ti, V, Cr, Mn, Co, Ni, Cu and Zn) in the ferromagnetic iron nitride gamma' - Fe4N are investigated in molecular cluster calculations with the discrete variational (DV) method. The calculations rely on the local spin density approximation of the density functional theory. The cluster is embedded in the long-ranged Coulombian crystal field potential, consisting of 300 atoms. The magnetic moment (mu), hyperfine magnetic field (H-c), density of states (DOS) and charge transfer are obtained for the central atom of each cluster. The results indicate that, at corner iron sites (named FeI), all these atoms behave as magnetic impurities, being that the Mn, Cr and Co atoms exhibit the largest mu value. At face centered iron sites (named FeII), except for Cu, all the others atoms are magnetic impurities, with the largest mu values belonging to the Mn, V and Co impurities. At both FeI and FeII sites the Mn atom has the largest H-c value. The N atom still acts as an acceptor for electrons, at both nonequivalent iron sites