Effect of atomic relaxation on the magnetic moment of Fe, Co, and Ni dimers supported on Cu(001)

Self-consistent field molecular orbital theory and Korringa-Kohn-Rostocker (KKR) Green's function method based on density functional formalism are use d to study the binding energies, electronic structure and magnetic properti es of Fe, Co and Ni dimers supported on Cu(0 0 1) surface. Molecular orbita l calculations are carried out on a cluster model where 28 Cu atoms are use d to model the substrate. Comparisons of these results with the KKR - calcu lation that treat the substrate as unrelaxed semi-infinite system show that the cluster model can adequately explain the properties of the supported d imers. While supported Fe and Co dimers have larger moments than their bulk values, magnetization vanishes for Ni-2 adsorbed on the substrate. The eff ect of substrate relaxation on the properties of deposited dimers is then s tudied using the cluster model. Relaxation is found to have no effect on th e magnetic character of these systems. The results are discussed in the lig ht of recent matrix isolation experiments on magnetic clusters. (C) 2001 Pu blished by Elsevier Science B.V.