Driving force for the electromigration of an impurity in a homogeneous metal

Abstract

Through a microscopic analysis the thermodynamic definition of the effective valence as the flux of electric charge associated with a unit flux of the solute is shown to be equivalent to the usual definition in terms of the force acting on the impurity in an electric field. Using the thermodynamics of irreversible processes, we show that the force acting on an impurity is proportional to its specific resistivity in the host metal, whatever the strength of the impurity potential.