Preparation of Zinc Oxide Nanoparticles Coated with a Composite Dopants’ Layer

[1, 2]. Zinc Oxide varistor is a polycrystalline ceramic which has become technologically important because of their highly nonlinear electrical characteristics enabling them to be used as reversible, solid-state switches with large-energy-handling capabilities. But to achieve the superior electrical properties, zinc oxide must be doped with Bi2O3, Sb2O3 and other transition-metal oxides or rare earth metal oxides.Conventional mixing method with milling can hardly lead to homogenous composites powders. This concern becomes more serious if using the zinc oxide nanopowders as the starting materials. Recently, some chemical methods have been introduced to overcome the homogeneity challenge in varistorsConsidering the facts that dopants are needed in the grain boundries of zinc oxide grains, coating the zinc oxide powders with a layer of dopants looks like a promising way to achieve high homogeneity and enhanced electrical properties. Solution coating of micron [3, 4] and sub-micron [5] ZnO particles were performed previously. But there has been no study carried out on the coating of ZnO nanopowders. In this study we aim at preparing the Solution-Coated Zinc Oxide nanopwders