Molecular dynamics investigation of the structural and thermodynamic properties of gold nanoclusters of different morphologies

摘要

Gold nanoclusters in the size range of 3-8 nm in diameter (923-10179) atoms were studied using the embedded atom method (EAM) "glue" potential. Three common structural morphologies for gold nanoclusters were considered: Icosahedral, defected icosahedral, and amorphous. The clusters were structurally relaxed and then analyzed by a structure measure technique using planar graphs. The free energies for the different cluster morphologies are also predicted as a function of cluster size. We show that glue potential can correctly predict the most stable structures observed in experiments from molecular dynamics simulations within the nanoclus-ter size range we considered and that the effect of surface disorder is important in considering the stability of the nanoclusters.