DC conductivity in polycrystalline metals for bulk and thin-film samples

Abstract

A new description of the DC conductivity in polycrystalline bulk metal and thin metal films is proposed in which isotropic background scattering and scattering due to grain boundaries are considered simultaneously. The general formula for the relaxation time for partly diffuse and partly specular scattering grain boundaries is obtained. The well known Mayadas and Shatzkes and Pichard-Tellier and Tosser models represent special cases of the author's description. For appropriately high specular reflection and small transmission coefficients of electrons through the grain boundaries a negative value of the temperature coefficient of the resistivity is obtained.