Article

Zinc oxide varistors are semiconductor ceramics which are caused by grain boundaries and microstructure of varistor. In this paper, the effect of sintering temperature on electrical properties of zinc oxide varistors is studied. Alteration of sintering temperature changes the varistor density, inner pores and concentrators in grain boundary which affects the electrical and mechanical properties of zinc oxide varistor. Bismuth oxide melts at a temperature lower than sintering temperature and forms the liquid phase. Then the added metallic oxides to the varistor are dissolved in antimony oxide grains and form the spinel phase.