Strain Scattering by Vacancies and Impurities in Metals

A simple model is proposed by means of which nearest neighbor displacements round a vacancy and an impurity in a metal may be taken into account in calculating excess resistivities. Using Tewordt's calculated nearest neighbor displacement for a vacancy in copper we obtain from our model an excess resistivity of 0.94 {μ}ohm cm per atomic percent. The same model without strain yields 0.97 {μ}ohm cm. The case of silver impurities in copper is also considered and it is shown that a radial increase of {~}3% in the nearest neighbor distance is sufficient to account entirely for the observed excess resistivity.