Hyper-quenched amorphous CrMnFeCoNi high-entropy alloy enabling the formation of body-centered cubic counterpart

CrMnFeCoNi is a prototypical high-entropy alloy (HEA), along with other 3d metal HEAs, that typically displays a paramagnetic face-centered cubic (fcc) phase when prepared under normal conditions. While theoretical calculations indicate that the ferrimagnetic body-centered cubic (bcc) phase of CrMnFeCoNi has comparable total energy to the fcc phase, it has not yet been observed experimentally. In this study, we successfully produced this metastable bcc phase by annealing an amorphous film and measured the temperature-induced crystallization processes. As a fundamental thermodynamic variable, pressure can effectively alter the bulk density and local atomic structure. Based on the predicted hexagonal close-packed (hcp) ground state, it is speculated that an amorphous (bcc)-hcp transition could occur, and this could be explored further using high-pressure X-ray diffraction.