Energetic Landscapes and Diffusion Properties in FeCu Alloys

The thermodynamic and kinetic properties of Fe-Cu alloys are studied by ab initio calculations, in the framework of a multiscale modeling of precipitation kinetics. The configuration energies at various compositions, the solute migration and binding energies, as well as the vacancy formation and binding energies are computed. The effects of the local copper distribution on the migration barriers are considered. We show that a simple diffusion model with effective interactions on a rigid lattice, which includes a description of the saddle-point configurations, captures the main features of the energetic landscapes explored by the vacancy during its diffusion in dilute and concentrated configurations.