Electronic conductivity of PbO2–xAg2O–0.75C system

Abstract

Investigation on phase transformation and electrical transport are carried out for PbO2–xAg2O–0.75C composite alloys. When the Ag2O content decreases, a percolation effect takes place near x = 0.275 for the distribution of the metallic particles embedded in the insulator matrix. With decreasing Ag2O content, the temperature dependence of resistivity of the composites changes from a typical metallic behaviour to an insulating one. A metal–insulator transition appears in the PbO2–0.275Ag2O–0.75C composite, with decreasing temperature. The electronics in the PbO2–0.23Ag2O–0.75C composite are described by hopping conductivity in terms of the variable-range-hopping model.