Predicting the phase stability of multi-component high entropy compounds

TL;DR

This paper introduces a first-principles method to predict the formation feasibility and phase stability of multi-component high entropy oxides, validated against known compounds and extended with Monte Carlo simulations.

Contribution

It develops a novel descriptor-based approach combined with Monte Carlo simulations to predict phase stability and secondary phases in high entropy compounds from first principles.

Findings

Successfully predicted entropy stabilized oxide (MgCoCuNiZn)O.

Provided a method to evaluate secondary phase formation.

Validated predictions against experimental data.

Abstract

A generic method to estimate the relative feasibility of formation of high entropy compounds in a single phase, directly from first principles, is developed. As a first step, the relative formation abilities of 56 multi-component, AO, oxides were evaluated. These were constructed from 5 cation combinations chosen from A={Ca, Co, Cu, Fe, Mg, Mn, Ni, Zn}. Candidates for multi-component oxides are predicted from descriptors related to the enthalpy and configurational entropy obtained from the mixing enthalpies of two component oxides. The utility of this approach is evaluated by comparing the predicted combinations with the experimentally realized entropy stabilized oxide, (MgCoCuNiZn)O. In the second step, Monte Carlo simulations are utilized to investigate the phase composition and local ionic segregation as a function of temperature. This approach allows for the evaluation of potential secondary phases, thereby making realistic predictions of novel multi-component compounds that can be synthesized.