Prediction of Single-Phase High-Entropy Nitrides from First-Principles Calculations

Entropy-forming ability (EFA) is used as a descriptor to identify possible single-phase high-entropy nitrides (HENs) from eight cation candidates Al, Si, Ti, V, Cr, Zr, Nb, and Mo. Around 56 five-cation HEN compositions using density functional theory calculations of 2744 ten-atom supercells are evaluated. Ten HEN compositions with high EFA values are identified, and among them AlCrNbTiVN5 has the highest EFA value. Cation-nitrogen bond length statistics shows that HENs with small lattice distortion tend to have large EFA values. The elemental dependence analysis shows that silicon introduces largest lattice distortion and hence small EFA values, which provides useful guidance for element selection of single-phase HENs.