Characteristics of ZnOV2O5MnO2Nb2O5Er2O3 semiconducting varistors with sintering processing

The effects of sintering temperature on the microstructure, electrical properties, and dielectric characteristics of ZnOV2O5MnO2Nb2O5Er2O3 semiconducting varistors have been studied. With increase in sintering temperature the average grain size increased (4.5–9.5 μm) and the density decreased (5.56–5.45 g/cm3). The breakdown field decreased with an increase in the sintering temperature (6214–982 V/cm). The samples sintered at 900 °C exhibited remarkably high nonlinear coefficient (50). The donor concentration increased with an increase in the sintering temperature (0.60×1018–1.04×1018 cm−3) and the barrier height exhibited the maximum value (1.15 eV) at 900 °C. As the sintering temperature increased, the apparent dielectric constant increased by more than four-fold.