The interaction of conduction electrons with dislocations and grain boundaries in metals

Abstract

Progress in understanding the contributions of dislocations and grain boundaries to the residual electrical resistivity in metals is reviewed. Following a summary of experimental data on dislocation and grain-boundary resistivity, it is shown that the resistivity due to the latter can be simply understood in terms of the independent scattering of electrons by individual dislocations of the ordered arrays which form the boundaries. The significance of this observation in establishing the relative dominance of dislocation core scattering over strain-field scattering, so far as charge transport is concerned, is discussed. A brief review of the multitude of dislocation–electron scattering calculations which have appeared in the literature is presented. This shows that theories which neglect the core contribution have invariably failed to account for the order of magnitude of the observed resistivity, again suggesting that core scattering dominates the issue. A simple formula derived from a resonance model of the core-electron interaction is shown to yield dislocation (and hence grain-boundary resistivity) contributions in good agreement with experiment.