Scattering of Electrons in Metals by Dislocations

The problem of the change in electrical conductivity in metals upon cold-working is treated by the method of Koehler in which the scattering of electrons by pairs of parallel edge-type dislocations is assumed to be the major effect. A comparison is made between the electronic shielding assumed in the scattering potential used by Koehler and the shielding assumed by Landauer in a somewhat different treatment. The large effect of the discontinuity in the ionic displacement across the plane connecting the dislocation axes is shown to cancel that of a previously neglected term in the scattering potential. The scattering matrix element is evaluated, and the change in resistivity is computed by the perturbation method of Mackenzie and Sondheimer. Finally, the anisotropy in the resistivity is discussed, and it is shown that the slip direction is the direction of low resistivity.