Prediction of short-range order in CrMnFeCoNi high-entropy alloy

Abstract

To theoretically examine the short-range order (SRO) in CrMnFeCoNi high-entropy alloy, we performed first-principles-based Monte Carlo simulations. A significant change in the number of the first and second nearest neighbor (NN) pairs occurred around the Cr atoms: Cr–Cr and Cr–Mn first NN pairs decreased and the other pairs increased. The second NN pair showed the opposite trend. These changes led to the formation of L12-type ordering. This chemical SRO originates from the instability of the parallel-spin first NN pairs around the Cr atoms in the face-centered cubic structure. The Cr and Mn atoms tend to occupy the corner sites of the L12 structure to reduce the number of first NN Cr–Cr and Cr–Mn pairs. The degree of the L12-type ordering is approximately 0.3 in the range of the 2nd NN distance. The elastic modulus is predicted to increase by forming the chemical SRO, whereas the influence of the chemical SRO on the averaged structural properties is small.