Drag exerted on dislocation kinks in solid solutions

The theory of drag exerted on dislocation kinks by statistical density fluctuations of impurity atoms is generalized to the case of solid solutions. The conditions of the transition to anomalous kink drift, which is characterized by a nonlinear time (t) dependence of the displacement x (x ∼ tδ, δ < 1), are obtained. The related consequences for the dislocation mobility and the plastic flow of a solid solution are derived. The theory is illustrated through calculating the concentration dependence of the deforming stress in a Ge1−cSic solid solution.