Experimental and theoretical study of tracer diffusion in a series of (CoCrFeMn)100-xNix alloys

Kottke Josua, Utt Daniel, Laurent-Brocq Mathilde, Fareed Adnan, Gaertner Daniel, Perrière Loïc, Rogal Łukasz, Stukowski Alexander, Albe Karsten, Divinski Sergiy V, Wilde Gerhard

Abstract

Tracer diffusion of all constituting elements is studied at various temperatures in a series of (CoCrFeMn)100−xNix alloys with compositions ranging from pure Ni to the equiatomic CoCrFeMnNi high-entropy alloy. At a given homologous temperature, the measured tracer diffusion coefficients change non-monotonically along the transition from pure Ni to the concentrated alloys and finally to the equiatomic CoCrFeMnNi alloy. This is explained by atomistic Monte-Carlo simulations based on a modified embedded-atom potentials, which reveal that local heterogeneities of the atomic configurations around a vacancy cause correlation effects and induce significant deviations from predictions of the random alloy model.