A numerical study of the freezing behavior of an unsupported nanometer-sizedAu droplet

Abstract

Molecular dynamics calculations have been employed to simulate the freezing transition ofan unsupported nanometer-sized Au droplet with a radius of about 3 nm. The freezingpoint was initially determined by gradually decreasing the droplet temperature bythe stochastic Nosè thermostat. A realistic cooling process was then simulatedstarting from a liquid Au droplet slightly above the freezing point and employing aHe gas collisional thermostat. Freezing nucleates at the droplet surface and ismediated by coalescence processes involving small clusters of solid-like atoms.