MELTING AND EVAPORATION OF ARGON CLUSTERS

Molecular dynamics simulation with a Nose-Hoover thermostat was used t o study melting and evaporation of free icosahedral argon clusters con taining 13 to 1415 atoms. Clusters of 147 atoms or less were found to melt at temperatures clearly below the bulk melting temperature in agr eement with previous results. Clusters containing 309 atoms or more we re observed to desorb atoms at temperatures where the core of the clus ter is solid. As a consequence of this a reliable determination of the ir melting temperatures using molecular dynamics was found to be compl icated. (C) 1997 American Institute of Physics.