High-throughput assessment of stability and mechanical properties of medium- and high-entropy carbides: Bridging empirical criteria and ab-initio calculations

Abstract

This study assesses the effectiveness of empirical stability descriptors — the normalized geometric packing parameter, lattice size difference, electronegativities mismatch, and the convex hull analysis based on information on mutually dissolving components, and ab-initio calculated entropy forming ability (EFA) for high-throughput materials discovery in high-entropy ceramics. A sample containing 53,130 medium and high-entropy carbide combinations from the Materials Project database has been analyzed, comparing solid solutions selected based on empirical descriptors and EFA calculations. The suitability of various electronegativity scales is evaluated, while Automatic FLOW (AFLOW) partial occupation (AFLOW-POCC) and special quasirandom structures (SQS) calculations provide insights into enthalpies, bulk moduli, and lattice parameters. It is shown that local distortions play a role in determining the stability of high-entropy ceramics and estimated lattice parameters, Young’s modulus, fracture toughness, and Vickers hardness by computational and experimental approaches. Our analysis demonstrates the efficacy of density functional theory (DFT) approaches for high-throughput screening and highlights the need for the further exploration of the cocktail effect on high-entropy ceramics’ mechanical properties.