Abstract
Doped zinc oxide nanopowder was synthesized by combustion method. The as-synthesized nanopowder was spray dried with three different (20, 25, 30) percentage of solid contents. Sintered samples were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD) showing the presence of secondary phases at intergranular spacing. The electrical behavior of the sintered samples was studied on the basis of the current density versus electric field (J-E) characteristics. A comparison on the electrical and microstructural properties of the varistors obtained by nanopowder and its spray dried granules was made. The best results on these characteristics were achieved through the spray drying route, obtaining a nonlinear coeficient of 167 and breakdown field of 8182 Vcm(-1) at a sintering temperature of 900 degrees C.