By synthesizing BiSbO4 material with a molar ratio of Bi2O3 to Sb2O3 of 0.6:1 and calcining it at 700 °C, a relatively pure compound was obtained. Additionally, the effects of varying BiSbO4 content on the microstructure and electrical properties of ZnO varistor ceramics were investigated. Results indicate that as BiSbO4 content increased from 0% to 3%, the voltage gradient of the varistor rose with increasing BiSbO4 content while leakage current gradually decreased. The nonlinear coefficient continued to rise, while the residual voltage ratio first decreased then increased. At a BiSbO4 content of 2%, outstanding electrical properties were achieved: voltage gradient (E1mA) = 346 V·mm−1, leakage current JL = 0.14 μA·cm−2, nonlinear coefficient α = 32, and residual voltage ratio K = 1.73. Furthermore, after undergoing a 100 kA surge, the U1mA value remained at 93.5% of its initial value, demonstrating outstanding surge stability. This provides a new approach for fabricating high-gradient, high-stability varistors.
Huang et al. (Thu,) studied this question.