MELTING OF THE GLASS-LIKE 19-ATOM GOLD CLUSTER

摘要

In this paper, the melting behaviors of the glass-like cluster Au_(19)are calculated and ana-lyzed by using standard microcanonical molecular-dynamics simulations. The calculatedresults show a multi-step melting process. The first stage involves the majority of thesurface atoms (14 atoms). An interesting phenomenon is that the minority of the surfaceatoms (4 atoms) are still in a solid-like state. The second stage involves all of the surfaceatoms. But there are two sites where the atoms stay for a relatively long time. The thirdstage corresponds to the frequent isomerizations involving all the surface atoms. Thefinal stage consists of isomerization transitions involving all of the atoms, including thecentral atom of the cluster. The unique melting processes lead to the unique features ofthe caloric curve, the root-mean-square bond-length fluctuation, and the heat capacityof the glass-like Au_(19).