Size effects on melting point based on surface energy and coordination number

Abstract

Size effect on melting point is closely related with the surface energy of nanoparticles, since the increased surface/volume ratio. As the nanoparticle’s size decreases, there have some different surface shape existing, which makes the coordination number are different from each other. Both the surface energy and coordination number of surface atoms are the necessary consideration in understanding the thermal stability of nanoparticles. So, a new model free of any adjustable parameters, based on size-dependent surface energy and calculation of the surface atomic coordination number of nanoparticles, is developed to predict the size-dependent melting point of nanoparticles. The model can be utilized to predict the thermal stability of low-dimensional materials within a large size range. The theoretical predictions in terms of the model are consistent with experimental evidences.