Magnetic properties of Ni and Fe clusters: A tight binding molecular dynamics study

We introduce an efficient approach which incorporates structural and magnetic ordering in transition metal clusters of sizes well beyond the range of ab initio techniques, The method combines the Hubbard model approximation with the tight binding molecular dynamics technique. Applications of the present scheme to Ni-n (n less than or equal to 7), and Fe-n (n less than or equal to 5) clusters show that while magnetic ordering does not affect the geometric ordering of Ni clusters, inclusion of magnetic effects strongly influences the structure of Fe clusters, forcing them to attain geometric configurations of higher symmetry than paramagnetic states.