Melting characteristics and strain-based mechanical characterization of single metal nanoparticles

In this study, the melting process of six single transition metal nanoparticles (radius of 2 nm) of Ag, Au, Co, Cu, Pd, and Pt was systematically investigated by molecular dynamics method. The melting points of these nanoparticles were determined by the variation curve of atomic average potential energy with temperature. The Honeycutt–Andersen (HA) index indicates that with increasing temperature, the six nanoparticles transformed from fcc structure to “others” structure types. With further increase in the temperature to the melting point of the nanoparticle, a sudden change in the structure was also observed. In addition, the melting process of nanoparticles was characterized by atomic local shear strain, indicating a clear dependence of atomic local shear strain on temperature. When the nanoparticles undergo solid–liquid phase transition, all atoms have high local shear strains with obvious local distortions and deformations.