Search for Significant Short-Range Ordering in Medium-Entropy Alloys Tr-Co-Ni (Tr = Cr, Mn, and Fe)

Abstract

Neutron total-scattering experiments were conducted to search for signatures of the short-range ordering in medium-entropy alloys Tr-Co-Ni (Tr = Cr, Mn, and Fe). The reduced pair distribution function of the Mn-Co-Ni sample clearly deviates from that of the fully random face-centered cubic structure, whereas those of the as-quenched Cr-Co-Ni and Fe-Co-Ni samples can be explained with an almost random face-centered cubic structure model. The results of neutron thermal analyses and reverse Monte Carlo structure modeling indicate a possible compositional and/or magnetic short-range ordering in the Mn-Co-Ni system.