Effect of the character of the (Ni, Pd) cluster/graphene interatomic bonds on the thermosize effects and structural-isomeric transitions

Abstract

The thermal evolution of nanoclusters is studied by molecular dynamics simulation to analyze the nucleation and kinetics of the kinetic processes that determine the basic factors of the onset of premelting and the loss of thermal stability of a two-dimensional system of transition-metal (Pd, Ni) nanoclusters located on a graphene substrate. A comprehensive analysis reveals the effect of the initial structural characteristics of nanoclusters, the heating conditions, and the kinetic factors during thermally activated diffusion on the nanostructuring in the thermal evolution of the nanoclusters. This evolution includes the following stages: isomerization, quasi-melting, and the decomposition of a given regular structure; it is classified as an order-disorder transition and as an analog of phase transitions in macroscopic systems on the nanoscale. © 2012 Pleiades Publishing, Ltd.