Abstract: “Because of its wide range of interesting applications including varistor devices, zinc oxide (ZnO) has been extensively studied by several researchers. Pure and 1%mol bismuth doped ZnO nanopowders have been synthesized by sol-gel method to study the effect of sintering temperature of phases alpha, beta and delta on the electrical varistors behavior. The used temperatures were: 650 degree Celsius, 730 degree Celsius, 800 degree Celsius and 900 degree Celsius. The investigations were made by XRD and SEM to determine the structural properties and the Bi intergranular phases. To connect these results to varistor effect, eclectic characteristics J (E) were plotted. Generally, a reasonable amount of Bi2O3 is sufficient to improve the non-ohmic behavior of ZnO-Bi2O3 binary varistors.”

Keywords: Semiconductors, ZnO-Bi2O3 , α, β -Bi phases, ZnO varistors.