A mathematical analysis of diffusion in dislocations. II. Influence at low densities on measured diffusion coefficients

For pt.I see ibid., vol.14, p.3863 (1981). Previous calculations are applied to estimate the contribution relatively small concentrations of dislocations of dislocations make to the diffusion coefficients defined by appropriate gradients of the initial part of conventional tracer penetration plots and usually presumed to represent volume diffusion. A first-order expression is derived for the effective, or dislocation perturbed, diffusion coefficient as a function of dislocation density using an empirical analytic representation of the computed numerical values of mean tracer concentration as a function of penetration distance.