Study on the electrical and physical characteristics of ZnO varistor according to the sintering temperature

This study investigates the electrical and physical characteristics of ZnO varistor according to the sintering temperature range from 600 °C to 1300 °C. Specimens are prepared with bismuth, antimony and other metal oxides. The composition of ZnO varistor is fixed only one batch. And the microstructure of varistor samples is observed by a FE-SEM & EDS. according to the maximum sintering temperature, the microstructure of ZnO varistors is changed involving both electrical and thermal property changes. Namely, the specimen which has sintering temperature range from 950 °C to 1150 °C shows better electrical and thermal properties than the others. Furthermore, Dielectric constant and nonlinear coefficients are strongly influenced by maximum densification temperature.