Modeling the Size-Dependent Solid–Solid Phase Transition Temperature of Cu₂S Nanosolids

Abstract

The present study provides a simple model to predict the favored phase of Cu2S nanosolids upon variation of their size, shape, and temperature. Insight into the phase stability at the nanoscale will aid in the design of new nanomaterials. A study of the solid–solid phase transition demonstrated that the low-chalcocite to high-chalcocite transition temperature of Cu2S nanowires increases with increasing wire diameter consistent with recent experimental data.(31) At ambient temperature, the high-chalcocite phase is the most stable phase for nanofilms with a thickness below 1.5 nm, nanowires with a diameter below 3 nm and nanoparticles smaller than 4.5 nm, all in agreement with experimental observations.