Linear response theory of the electromigration driving force in liquid alloys

Abstract

Diagrammatic techniques are applied to the discussion of the average electromigration driving force in the weak-scattering limit. The Faber expression is confirmed to lowest order in the electron—ion potential but, when the scattering is described by the single-centre t matrix, a new term appears which involves matrix elements off the energy shell. Explicit expressions for these matrix elements are given in terms of the solution of the radial wave equation.