Structure and temperature dependence of resistance in very high resistivity thick films

Microstructures have been examined for superhigh-resistivity thick films having typical resistivities of 108–1011 Ω/□ and based on Sn0.9Sb0.1O2-Sb2O4 and Pb2Ru2O6 powders, amorphous glass, and crystallizing glass. The temperature dependence of the resistance has been measured at 77–870 K. Films based on Sn0.9Sb0.1O2-Sb2O4 mixtures have a chain structure, which consists of a network of particles of the conducting phase and groups of them, which are arranged around the particles of glass. There is a random distribution of the Pb2Ru2O6 particles in the glass matrix, and mutual diffusion occurs between the phases. The temperature dependence of the resistance is of activation type, which is due to carrier transport through the thin glass layers.