It was recalled that Cu played an important role in the embrittlement of pressure-vessel steels under radiation, and entities which contained both Cu atoms and vacancies seemed to appear as a consequence of displacement cascades. Characterization of the stability as well as of the migration of small Cu–vacancy complexes was therefore necessary in order to understand and simulate the formation of such entities. For instance, cascade aging studied by kinetic Monte Carlo or by rate theory models required good characterization of such complexes. An investigation was made here, using ab initio calculations based upon density functional theory, of point defects and small defects in dilute Fe-Cu alloys. The structures of small Cu clusters and Cu–vacancy complexes were determined, as well as their formation and binding energies. Vacancy migration energies in the presence of Cu atoms were calculated and analyzed. All of the results were compared to figures obtained using empirical interatomic potentials.

Ab initio Contribution to the Study of Complexes Formed during Dilute FeCu Alloy Radiation. C.S.Becquart, C.Domain: Nuclear Instruments and Methods in Physics Research B, 2003, 202, 44-50