Kinetics of point defect absorption by sinks effect of point defect properties and surrounding microstructure

International audienceThe behavior of materials under irradiation crucially depends on the microstructure evolution, which is driven by the absorption of point defects by the sinks (dislocations, cavities and loops). Cluster dynamics is a noteworthy theoretical tool of material science that can predict the microstructure evolution over long physical time. In this approach, the absorption kinetics of point defects depends on the values of sink strengths. An accurate evaluation of sink strengths is therefore necessary to obtain a reliable prediction of the materials evolution under irradiation.This work aims at computing accurate sink strength values by explicitly simulating the diffusion of point defects using Object Kinetic Monte-Carlo simulations. This study emphasizes the importance of elasticity on the diffusion of point defects. More precisely, elastic interactions between sinks and point defects are taken into account, and defects are described by their elastic dipoles and polarizabilities at stable and saddle points, which are computed by ab initio calculations.Our study of point defect migration to single sinks reveals that the anisotropy of point defects at saddle points is a key parameter in sink strength calculations, as it strongly affects the migration paths of point defects. We have also analyzed the migration of point defects in microstructures containing several sinks to investigate the effect of the neighboring clusters on sink strengths