Thermopower measurements on copper and silver at low temperatures with particular attention to scattering by residual magnetic impurities

Abstract

The improvement in the resistance ratio of copper, when annealed in oxygen, has been explained in terms of the oxidation of transition metal impurities. Thermopower measurements have been used to study the effectiveness of the treatment. It is found that the oxidation process does not completely eliminate the magnetic scattering but reduces it considerably. Silver-iron alloys subjected to similar treatment lose all their magnetic scattering. Measurements have also been carried out on plastically deformed copper and silver to study the effects of the introduction of lattice defects on the resistance and thermopower. Changes produced in the diffusion and phonon drag components of the thermopower are discussed.