Magnetic properties of Co/Cu and Co/Pt bimetallic clusters

The ground state structures of Co/Cu and Co/Pt clusters are obtained by empirical genetic algorithm, and further optimized using the density functional theory with generalized gradient approximation. For Co13, Pt13 and Cu13, they show perfect Ih symmetry. The structures of bimetallic clusters are slightly distorted configuration of Co13. The average magnetic moment of Co13 is 2.38 μB/atom, and that of Cu13 and Pt13 is nonzero. The local moments of the central atom are smaller than that of the surface ones for Co13 and Cu13. But the cases are not held for Pt13. The total magnetic moment of clusters Co/Pt monotonously decreases with increasing the concentration of Pt atoms. But the things are much more complicated for clusters Co/Cu, and the reasons are discussed in detail.