BIMETALLIC NANOSTRUCTURES .1. GENERAL-ASPECTS AND THE GROUND-STATE

A systematic study of ordering and segregation in bimetallic nanoclusters is presented. Icosahedral and cubo-octahedral clusters with a total number of particles, N = 55 and 147, are studied. The spatial distribution of the two components, in the cluster, is obtained by calculating the free energy within the regular solution model. Depending on the heat of mixing and on the difference in the cohesive energy of the components, and as a consequence of the large surface to volume ratio, one obtains a variety of phases characteristic only of the nanosystems. By comparing the total energies of the icosahedron and the cubo-octahedron the equilibrium shape is obtained as function of the cluster size and of the interaction energies. © 1990.