Molecular Dynamics Simulation Study of the Melting of Silver Nanoparticles

Abstract

In the application process of nanoparticles, the melting process plays an important role. Holding the melting characteristics of nanoparticles can essentially improve the correlative technical level. To study the melting characteristics of silver nanoparticles, melting processes of silver nanoparticles are investigated using molecular dynamics simulation. Simulation results show that the microscopic melting process of nanoparticles is the uneven transition process of atomic structures from order to disorder. Also, the melting point of 3 nm particle with 856 atoms is about 815 K and the heat capacity of nanoparticles is negative near the melting temperature. The dominant mechanisms of melting process are analyzed from potential energy temperature relationship, radial distribution function, mean square displacement and atomic evolution configuration. We also found that nanoparticles bunch up due to high surface energy for multi-nanoparticles when the temperature is lower than the melting point. And, when nanoparticles melt into droplet, the liquid nanoparticles have stronger liquidity and automatically reduce to spherical structures due to the role of surface tension.

Keywords:

• Melting
• nanoparticles
• characteristics
• molecular dynamics

Acknowledgments

This project was supported by the National Natural Science Foundation of China (90923041, 51275122), the Key Laboratory of Micro-systems and Micro-structures Manufacturing (Harbin Institute of Technology), Ministry of Education (HIT.LOF.2011041), the Fundamental Research Funds for the Central Universities (HIT.NSRIF.201171) and the 111 Project of China (B07018).