Enforcing local equilibrium of point defects near sinks in object kinetic Monte Carlo simulations

Abstract

A model for the emission of point defects by point defect sinks is proposed for object kinetic Monte Carlo simulations. Local equilibrium of point defects in the vicinity of sinks is ensured by construction, even if elastic interactions are taken into account for the diffusion of point defects. The emission of vacancies by dislocation segments is treated in detail and validated numerically. The model is then used to simulate the annealing of a vacancy Frank loop in a system containing surfaces. Results are in overall good agreement with analytical formulas, which are based on the approximation of instantaneous equilibration of the vacancy field during the loop evolution process. For small loops the shrinkage is so rapid that this quasi-static approximation is no more valid.