Simulation of displacement cascades in Fe 90Cr 10 using a two band model potential

Abstract

Molecular dynamics (MD) simulations of displacement cascades, with recoil energies up to 50 keV, have been performed in Fe 90Cr 10 and Fe using a recently developed two band embedded atomic model (2BM) potential that correctly describes the mixing enthalpy and the binding energy of the mixed dumbbell configurations. Comparisons between results obtained with the 2BM potential fitted to different data sets, a one band model (1BM), and another existing FeCr-potential previously used for similar calculations were done, showing differences in the vacancy clustered fraction and the Cr content in interstitials predicted by the potentials. The 2BM potential resulted in roughly the same concentration of Cr in interstitial positions as in the matrix, and the 1BM, which incorrectly predicts a positive heat of mixing, predicted even smaller concentrations. The calculated short range order parameter is around zero for the 2BM, and takes positive values within the 1BM, as expected from the mixing enthalpies.