Macro-to-Nano Scale Modeling the Effect of Surface Energies on Surface Melting Phenomena in Metallic NanoTubes/Wires

Abstract

Among nonomaterial with different geometric shapes, nanotubes and nanowires received special attentions with increasing applications in electronic industry and nanorobotic due to their unique properties. Therefore, in order to study the fundamental properties of nanotubes/wires, in this paper we will focus on modeling the melting of different crystal surface of metallic materials. Although there are different models in literature based on change of cohesion energy or coordination number at nanoscale, here we present a generalized thermodynamics model which considers layer by layer melting of nanotubes/wires. This model considered the surface energy of solid-gas, liquid-gas and solid-liquid along with the effect of fcc, bcc and hcp crystallography of different metals and their different surface crystal plane orientations. During the analytical simulation of surface melting, different run have been performed for variable size of tubes/wires in order to involve the size effect at nanoscale. Calculation results of model will be presented for some metallic systems such as: Ni, Pb, Fe and Zn. Results of our calculations show good agreement with experimental results and other theoretical predictions in literatures. Our model provides a powerful tool to analysis melting phenomena of metallic nanotubes/wires at different crystal structures and surface plane orientations for various sizes at nanoscale.