Atomistic kinetic Monte Carlo simulations were a powerful tool to study the microstructural and microchemical evolution of alloys controlled by diffusion processes, under irradiation and during thermal ageing. In the framework of the FP6 Perfect program, two main approaches were applied to binary and multicomponent iron based alloys. The first one was based upon a diffusion model which takes into account vacancy and self-interstitial jumps, using simple rigid lattice approximation and broken-bond models to compute the point-defect jump frequencies. The corresponding parameters were fitted to ab initio calculations of a few typical configurations and migration barriers. The second method used empirical potentials to compute a much larger number of migration barriers, including atomic relaxations, and Artificial Intelligence regression methods to predict the other ones. It was somewhat less rapid than the first one, but significantly more than simulations using “on-the-fly” calculations of all the barriers.

Atomistic Kinetic Monte Carlo Studies of Microchemical Evolutions Driven by Diffusion Processes Under Irradiation. F.Soisson, C.S.Becquart, N.Castin, C.Domain, L.Malerba, E.Vincent: Journal of Nuclear Materials, 2010, 406[1], 55-67