Molecular dynamics computer simulations were used, together with a Finnis-Sinclair type of interatomic potential, to calculate the properties of point defects and to establish the threshold displacement energies for Cu and Au primary knock-on atoms. It was found that the most stable interstitial was the Cu-Cu<100> dumb-bell which was centered on a Cu site in the {100} planes which contained only Cu atoms. All of the configurations of a Au interstitial were unstable with respect to the formation of a Cu antisite defect plus a Cu-Cu<100> interstitial. The results were compared with those which resulted from using embedded-atom potentials, where the data for antisite defects were different to the present data on threshold displacement energies for Au recoils. That is, there were lower average values than those for Cu recoils; in contrast to the threshold energies of recoils of the oversized Al species in Ni3Al. However, in the case of Cu recoils, the threshold displacement energies were very similar to those found for Ni recoils in Ni3Al. This was particularly true of orientations in which Cu-Cu interactions predominated. A long replacement collision chain could be formed in crystals at 0K, without generating stable Frenkel pairs. The results were explained in terms of the structure, and atomic interactions.

Point Defect Properties and Threshold Displacement Energies in Cu3Au F.Gao, D.J.Bacon, S.Newall: Philosophical Magazine Letters, 1998, 77[5], 229-39