We investigate the short-range order (SRO) and phase stability of the equiatomic CoCrFeMnNi high-entropy alloy using cluster expansion supplemented by an eigen-decomposition analysis of the SRO parameters. Our results reveal that the primary ordering behavior is determined by strong Cr-Cr repulsive interactions, complemented by attractive heteroatomic Cr-X pairs in the first nearest-neighbor shell. This chemical affinity is consistent with the emergence of ordered local environments and appears to be a major contributor to the primary order-disorder transition. At lower temperatures, the spectral SRO analysis suggests two additional lower-temperature instabilities: a collective ordering instability and an Fe-rich local clustering instability.
@article{arxiv.2605.18219,
title = {Short-range order in the CoCrFeMnNi high-entropy alloy from cluster expansion},
author = {Wei Chen and Gian-Marco Rignanese and Geoffroy Hautier},
journal= {arXiv preprint arXiv:2605.18219},
year = {2026}
}