First-principles calculations on the structures, magnetic, and electronic properties of the (Fe2N)m(m=1-4) and (Fe3N)n(n=1-3) clusters

The structures, magnetic, and electronic properties of the ground-state (Fe2N)(m)(m = 1-4) and (Fe3N)(n)(n = 1-3) clusters have been investigated by using first-principles. The structure of the (Fe2N)(m)and (Fe3N)(n)clusters is a compromise that the N atoms approach more Fe atoms and the N atoms repel each other. The structural stabilities of the (Fe2N)(m)and (Fe3N)(n)clusters increase with the increasing of the N ratio except for the Fe(6)N(3)clusters. The (Fe2N)(m)(m = 1-4) and Fe(9)N(3)clusters exhibit more kinetic stabilities than pure iron clusters. The N substitution can decrease the average spin densities of small iron clusters except for the Fe(6)N(2)and Fe(8)N(4)clusters. The Fe-N bonds exhibit certain covalent bond characteristics.