Local chemical order in CrFeCoNiPd high entropy alloys

Abstract

High-entropy alloys (HEAs) have attracted considerable attention in recent years due to their exceptional mechanical and physical properties. However, the existence of local chemical order (LCO) in these alloys—particularly in equiatomic CrFeCoNiPd face-centered cubic HEAs—remains a subject of ongoing debate. In this study, we employ a robust and high-fidelity cluster expansion (CE) method, combined with Monte Carlo simulations, to investigate the potential presence of LCO in CrFeCoNiPd HEAs. Our CE model demonstrates high predictive accuracy, achieving a correlation coefficient of 0.987 for configurational energy. The analysis reveals distinct chemical short-range order, with a pronounced preference for Pd–Pd pairs. Moreover, significant nanoscale compositional fluctuations are observed, indicating a non-uniform distribution of elements within the alloy. These findings offer valuable guidance for future experimental and theoretical studies aimed at understanding chemical ordering phenomena in complex alloys.