Segregation and migration of species in the CrCoFeNi high entropy alloy

The formation and migration of intrinsic defects in the CrCoFeNi high entropy alloy has been investigated using ab-initio modeling. The ease of vacancy formation was found to vary depending on the element: vacancies formed by the removal of Fe, Ni and Co are positive while Cr has a negative vacancy formation energy and will precipitate out of the CrCoFeNi alloy. This mechanism may allow the formation of a corrosion passivating oxide layer, analogous to Cr behaviour in stainless steels. The migration and behaviour of intrinsic interstitial defects has also been investigated.