Thermal behavior of Cu–Co bimetallic clusters

Based on a Gupta-like many-body potential, we have investigated the thermal behavior of Co–Cu bimetallic clusters with n=18, 19, 20 by using Monte Carlo techniques. A relation between cluster melting temperature and Cu concentration is obtained. We find the melting behavior of a bimetallic cluster strongly depends on the component materials, stoichiometries, size and structure of the cluster. The structural transition between isomers or degenerated states happens in the 18-atom clusters. Local melting occurs in the Co13Cu5 cluster because of the segregation of Cu and a novel layered structure.