Exotic Supported CoPt Nanostructures: From Clusters to Wires

A bottom-up computational approach for designing exotic phases of supported metallic nanostructures is proposed and exemplified for the CoPt/ MgO(100) system. Magic polyicosahedral CoPt clusters, Frank-Kasper motifs that have no counterpart in bulk CoPt, are singled out in the gas phase and then deposited on a substrate that enhances their stability via a mechanism rationalized in terms of the many-body character of the metal/surface interaction. Both finitesize (nanoclusters) and one-dimensional (nanowires) structures can be so constructed, where one-layer Co interfacial segregation and the small size of the clusters suggest that their peculiar morphology can be reached and maintained via self-organization, while the wires appear to be robust with respect to necking instabilities.