Defect energetics in Fe–Cr alloys from empirical interatomic potentials

Abstract

Fe–Cr based alloys are considered as candidate structural materials in the design of next generation reactors. A good knowledge of the behavior under irradiation of these compounds is needed in order to have the best possible safety and longer lifetime in future nuclear plants. Density functional theory (DFT) calculations are only available for a few hundreds of atoms and in order to increase time and length scales it is necessary to have appropriate tools to continue the study in larger systems. In this work we perform a comparative study between two empirical interatomic potentials specially developed to study Fe–Cr alloys. The dependence of the calculated formation energy for vacancy, self- and mixed interstitials is investigated for both potentials in pure bcc Fe and pure bcc Cr. These results are compared to DFT values in the literature. Some small Cr clusters in substitutional positions have also been studied in bcc Fe.