The electrical properties of semiconducting ceramic composites which were made from n-type ZnO and p-type CuO were investigated. The conductivity increased with increasing CuO contents of between 1 and 95mol%. The impedance response exhibited 3 semicircles, thus indicating that 3 resistive elements contributed to the total resistance. A new model which was based upon the equivalent circuits was developed in order to explain the contribution which grain boundaries made to the resistance of the composite.

S.T.Jun, G.M.Choi: Journal of the American Ceramic Society, 1998, 81[3], 695-9