Exchange interaction and local environment effects on the magnetic properties of FeN clusters

The magnetism of FeN clusters is studied by using a d-band Hubbard-like Hamiltonian in the unrestricted Hartree-Fock approximation. The local magnetic moments, magnetic order, and average magnetization per atom are calculated for T0 as a function of the intra-atomic Coulomb exchange integral J. Different cluster sizes and structures are considered and local environment effects are analyzed. Both continuous and sharp (first-order-like) transitions in the local magnetic moments are obtained as a function J, which are related to changes in the local densities of electronic states and to redistributions of the spin-polarized charge density. Finite-size and structural effects are discussed, particularly by comparison with bulk results. © 1992 The American Physical Society.

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