Molecular dynamics simulations on the melting of gold nanoparticles

Abstract

AbstractMolecular dynamics is employed to study the melting of bulk gold and gold nanoparticles. PCFF, Sutton-Chen and COMPASS force fields are adopted to study the melting point of bulk gold and we find out that the Sutton-Chen force field is the most accurate model in predicting the melting point of bulk gold. Consequently, the Sutton-Chen force field is applied to study the melting points of spherical gold nanoparticles with different diameters. Variations of diffusion coefficient, potential energy and translational order parameter with temperature are analyzed. The simulated melting points of gold nanoparticles are between 615∼1115 K, which are much lower than that of bulk gold (1336 K). As the diameter of gold nanoparticle drops, the melting point also descends. The melting mechanism is also analyzed for gold nanoparticles.Keywords: molecular dynamics simulationnanoparticlemelting pointgoldmolecular simulationsolid–liquid transition AcknowledgementsSupports from the Program for New Century Excellent Talents in University, Ministry of Education, China (NCET-07-0313) and Guangdong Natural Science Foundation (No. S2011010002078) are gratefully acknowledged. The computational resources for this project are provided by SCUTGrid at South China University of Technology.