A mixed enthalpy-entropy descriptor for the design and high-throughput screening of high-entropy materials

Over recent years, considerable research has been carried out to understand the design principles for the stability and synthesis of high-entropy materials (HEMs). In most cases, either enthalpy- or entropy-based formalism has been adopted to build a descriptor to understand the composition-structure-property relationships of these complex systems. However, both thermodynamic quantities play crucial roles in governing the stability of HEMs. In this work, we propose a Mixed Enthalpy-Entropy Descriptor (MEED), which features an actuating enthalpy-entropy competition that underlies the stability and formation of solid solutions. By using robust and efficient first-principles high-throughput screening of the carbides and 2D disulfides of metals (Hf, Nb, Mo, Ta, Ti, V, W, and Zr), the MEED successfully identifies all experimentally reported single-phase HEMs in these two groups comprising four, five, and six principal metal elements. The known HEMs are not only clearly separated from those element combinations that form multiple phases, but also the relative magnitudes of their growth temperatures have been estimated. With MEED, additional new high-entropy carbides and 2D high-entropy transition metal disulfides have been predicted.