Analyses of surface and core atoms in a platinum nanoparticle

Abstract

Molecular dynamics simulations of a platinum nanocluster consisting 250 atoms were performed at different temperatures between 70 K and 298 K. The semi-empirical, many-body Sutton-Chen (SC) potential was used to model the interatomic interaction in the metallic system. Regions of core or bulk-like atoms and surface atoms can be defined from analyses of structures, atomic coordination, and the local density function of atoms as defined in the SC potential. The core atoms in the nanoparticle behave as bulk-like metal atoms with a predominant face centered cubic (fcc) packing. The interface between surface atoms and core atoms is marked by a peak in the local density function and corresponds to near surface atoms. The near surface atoms and surface atoms prefer a hexagonal closed packing (hcp). The temperature and size effects on structures of the nanoparticle and the dynamics of the surface region and the core region are discussed.