METAL-CLUSTER COMPOUNDS - MODEL SYSTEMS FOR NANOSIZED METAL PARTICLES

Meta-cluster compounds can be exploited advantageously to study the ev olution, with increasing size of the molecules of the physical propert ies of metal clusters from molecular to bulk-metal behavior. The metal -cluster molecules are well-defined, stoichiometric, chemical compound s. The molecules consist of a metal core of a variable number of atoms , surrounded by a shell of ligand atoms or molecules. Depending on the compound, the type of metal atom may be varied, whereas the core size can be changed from a few up to several thousands of atoms. According ly, these materials provide excellent model systems for monodisperse m etal particles, embedded in a dielectric matrix, and can be investigat ed by the well-known experimental techniques of solid-state physics. ( C) 1998 John Wiley & Sons, Ltd.