Point-defect diffusion in a strained crystal

Abstract

The diffusion equations for interstitials and vacancies in the field of an edge dislocation are numerically solved within a theoretical model that takes into account the full lattice and defect symmetry in the migration jump. The defect concentration is calculated within two different approximations: In one, only the defect drift contribution to the diffusion is considered, while in the other, the drift and gradient terms are included as well as a constant defect generation rate. In this second approximation the steady-state concentration is calculated. The influence on the solutions of an external uniaxial stress with different orientations with respect to the dislocation is studied. Numerical results for the dislocation sink strength are obtained for vacancies and interstitials in Cu. These are compared with previous approximations in the literature. The relevance of the results to the establishing of a radiation creep mechanism is discussed.