Enhancement of Microstructure Development and Current-voltage Characteristics of ZnO-Bi2O3 Varistor Ceramics Sintered with Sintering aids at the Low-Temperature

Abstract

Abstract ZnO-Bi2O3 based varistor ceramics doped with SnO2 or with SnO2, B2O3 and SiO2 were prepared by traditional solid–state reaction method respectively. The microstructure and properties of samples sintered at a low temperature range from 910 to 950°C were studied. Results show that: by low-temperature sintering, the sintering aids can improve the sample’s density and homogeneity, and therefore the overall properties of the samples. It was found that the samples sintered at 910°C with SnO2 as sintering aid possess the best performance, and the breakdown voltage is 1368 V/mm, nonlinear coefficient is 12.2, and the leakage current is less than 0.1 μA.