The extra-resistivity due to vacancies in copper, silver and gold

Summary Lattice defects in metals, for instance dislocations, interstitial atoms or vacancies, such as can arise from coldworking or neutron irradiation, cause an extra-resistivity. In this paper the resistivity due to vacancies is calculated for copper, silver and gold. The conduction electrons are supposed to be completely free. The scattering area of a vacancy in Cu is found from the field of this atom, for which we have takena) the negative of the Hartreefield of Cu⁺,b) a suitably chosen rectangular field. The results of these calculations being about the same, the case of Ag and Au is treated, using a rectangular field only. It then turns out that for monovalent metals the extra-resistivity per percent vacancies is proportional to the atomic radius. The results for Cu, Ag and Au are, respectively, 1.3, 1.5 and 1.5 cm/% vacancies; they enable us to calculate the number of vacancies in certain cases. For Cu a vacancy has about the same influence on the resistivity as a dissolved Ni-atom.