First principles thermodynamical modeling of the binodal and spinodal curves in lead chalcogenides

TL;DR

This study combines ab-initio calculations, cluster expansion, and thermodynamic modeling to accurately predict phase diagrams and spinodal decomposition in lead chalcogenides, revealing insights into their low thermal conductivity.

Contribution

It introduces a novel integrated computational approach that improves the accuracy of phase diagram predictions for lead chalcogenides using online quantum data.

Findings

Results agree with experimental data

Consolute temperatures are significantly improved

Spinodal nanostructures linked to low thermal conductivity

Abstract

High-throughput ab-initio calculations, cluster expansion techniques and thermodynamic modeling have been synergistically combined to characterize the binodal and the spinodal decompositions features in the pseudo-binary lead chalcogenides PbSe-PbTe, PbS-PbTe, and PbS-PbSe. While our results agree with the available experimental data, our consolute temperatures substantially improve with respect to previous computational modeling. The computed phase diagrams corroborate that the formation of spinodal nanostructures causes low thermal conductivities in these alloys. The presented approach, making a rational use of online quantum repositories, can be extended to study thermodynamical and kinetic properties of materials of technological interest.