EMBEDDED-ATOM METHOD COMPUTATIONS OF STRUCTURAL AND DYNAMICAL PROPERTIES OF CU AND AG CLUSTERS ADSORBED ON PD(110) AND PD(100) - EVOLUTION OF THE MOST STABLE GEOMETRIES VERSUS CLUSTER-SIZE

The structural stability of one- and two-dimensional arrangements of Cu and Ag clusters adsorbed on Pd(110) and Pd(100) is investigated as a function of cluster size by using embedded atom method potentials. In Cu/Pd(110), we find a remarkable stability of one-dimensional chains over two-dimensional compact arrangements, which increases with cluster size N while the opposite trend (decreasing stability with increasing size) is found in the case of Ag/Pd(110). On Pd(100) two-dimensional structures are the most stable. The diffusion mechanisms for the adatom movement on Pd(110) are elucidated via static computations and described in detail for migration along the [001] direction.