The mobility and the stability of small vacancy (V) and copper-vacancy (Cu-V) clusters played a key role in the microstructural evolution of Fe-Cu alloys under irradiation, but these were largely unknown parameters that could not be experimentally measured. These parameters had therefore been determined using atomistic kinetic Monte Carlo simulations, where the vacancy jump activation energies as functions of the local atomic environment had been previously calculated using a molecular dynamics code and tabulated for use in the atomistic kinetic Monte Carlo code. This method allowed relaxation effects to be implicitly included in the model and possible differences between the predictions of different interatomic potentials to be evaluated. the mobility, lifetime and mean free path of clusters containing up to six vacancies and Cu-V complexes containing up to four components was studied. In the case of the VV and Cu-V pairs, the results obtained with different many-body potentials were compared with ab initio results. All results were briefly discussed in terms of their impact on the microstructure evolution in irradiated FeCu alloys.

Stability and Mobility of Small Vacancy and Copper-Vacancy Clusters in BCC-Fe: an Atomistic Kinetic Monte Carlo Study. F.G.Djurabekova, L.Malerba, C.Domain, C.S.Becquart: Nuclear Instruments and Methods in Physics Research B, 2007, 255, 47-51