Atomistic simulation of CdTe solid-liquid coexistence equilibria

Abstract

Atomistic simulations of CdTe using a Stillinger-Weber (SW) interatomic potential were undertaken to model the solid-liquid phase equilibria of this important compound semiconductor. Although this potential has been used by others to study liquid CdTe and vapor-liquid interface, it is based on fitting parameters optimized only for the zincblende solid. It has not been fully explored as a potential for solid-liquid phase equilibria until this work. This research reports an accurate determination of the melting temperature, ${T}_{\text{M}}=1305\text{ }\text{K}$ near $P=0$, the heat of fusion at melting, and on the relative phase densities with a particular emphasis on the melting line. The SW potential for CdTe predicts a liquid with a density slightly less than that of the solid and, hence, the pressure-temperature melting line has a positive slope. The pair-correlation structure of the liquid is determined and favorably compared to neutron-scattering data and to ab initio simulations. The liquid-solid interface is discussed using density profiles and a short-range order parameter for models having principal orientations along $⟨100⟩$, $⟨110⟩$, and $⟨111⟩$ crystallographic directions.