Order–disorder competition in equiatomic 3d–transition–metal quaternary alloys: phase stability and electronic structure

We use high-throughput first-principles sampling to investigate competitive factors that determine the crystal structure of high-entropy alloys (HEAs) and energetics dependence stable phase on atomic configuration ‘semi-ordered’ L12, D022, random solid solution (RSS) phases equiatomic quaternary comprising four six constituent elements (Cr, Mn, Fe, Co, Ni, Cu). Note that, generally, an FCC lattice consists L12/D022 sublattices. In this study, we call a where one sublattices is fully occupied by certain element, whereas others are randomly other like RSS. Considering configurational entropy, demonstrate valence electron concentration (VEC) temperature crucial stability HEAs at finite temperatures, wherein ‘rather enthalpy-driven’ ordered energetically more favorable than entropy-driven’ RSS phases. Some D022 with high VEC L12 phases, though both metastable. Furthermore, explore magnetic configurations identify origin enthalpy term. The calculations reveal antiferromagnetic atoms surrounded ferromagnetic stable. Relationships between ordering arrangements also discussed.