Melting and Crystallization of Free Copper and Nickel Nanoclusters using Molecular Dynamics Simulations

Abstract

Molecular dynamics simulations with second nearest neighbor modified embedded atom method have been performed on free-standing copper and nickel nanoclusters composed of 2048 atoms. Thermo-dynamical, dynamical and structural properties of the nanoclusters have been investigated during melting and crystallization process. Variation of potential energy, specific heat and self-diffusion coefficient of atoms during the phase transition have been used to determine the melting and crystallization points. Radial distribution function is used to characterize the structural changes of the nanoclusters. The melting and solidification profiles of both the nanoclusters showed hysteresis behavior, which is attributed to the undercooling effect during the solidification process. The melting temperature is about few hundreds of Kelvins higher than the crystallization temperature. The result shows that the melting and crystallization temperature of copper nanocluster are 1360[Formula: see text]K[Formula: see text][Formula: see text][Formula: see text]5[Formula: see text]K and 1090[Formula: see text]K[Formula: see text][Formula: see text][Formula: see text]5[Formula: see text]K, respectively, and those of the nickel nanoclusters are 1710[Formula: see text]K[Formula: see text][Formula: see text][Formula: see text]5[Formula: see text]K and 1390[Formula: see text]K[Formula: see text][Formula: see text][Formula: see text]5[Formula: see text]K, respectively.