Structural and magnetic properties of X12Y (X, Y=Fe, Co, Ni, Ru, Rh, Pd, and Pt) nanoalloys

We perform extensive ab initio density-functional calculations to investigate the structures and magnetic moments of the binary clusters X12Y (X, Y=Fe, Co, Ni, Ru, Rh, Pd, and Pt). Although all the binary clusters Fe12Y, Co12Y, Ru12Y, and Rh12Y, plus Ni12Y (Y=Rh, Pd, and Pt) and Pt12Y (Y=Ru, Rh, and Pd), retain, with more or less distortions, the structures of the corresponding pure X-13 clusters, the remaining binary clusters (i.e., a significant number of 12 of all the 42 cases) adopt geometries different from those of the corresponding pure clusters. Independent of the peculiarities of each family of binary clusters, the binding energies of all the binary clusters X12Ru are bigger than those of the pure X-13 clusters, while the binding energies of all the binary clusters X12Pd are smaller. The clusters investigated exhibit a variety of magnetic behaviors. In the case of Ni12Rh, we predict a remarkable magnetic cooperative phenomenon that can be attributed to electronic effects associated to the chemical environment through Ni-Rh hybridization. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3427292]