It was recalled that the behavior of Cu atoms in dilute solution in -Fe was important with regard to microstructural changes that occurred in ferritic steels under fast neutron irradiation. In order to investigate the properties of the atomic defects which controlled this behavior, a set of many-body interatomic potentials was developed for the Fe-Cu system. The procedures involved modifications which ensured their suitability for simulating atomic collisions at high energies. The effect of Cu upon the lattice parameter of Fe was in good agreement with experiment. The phonon properties of the pure crystals, and the effect of the instability of the metastable body-centered cubic Cu phase that precipitated during irradiation, were considered. The properties of point defects were investigated and it was found that the vacancy had lower formation and migration energies in body-centered cubic Cu than in -Fe. The self-interstitial atom had a very low formation energy in this Cu phase. The threshold displacement energy in Fe was calculated, as a function of the recoil orientation, for both Fe- and Cu-atom recoils. The differences between the energies for the 2 species were small.

G.J.Ackland, D.J.Bacon, A.F.Calder, T.Harry: Philosophical Magazine A, 1997, 75[3], 713-32