Preparation of doped ZnO nanopowders by refluxing method and applications in high voltage varistors
The doped ZnO nanopowders were successfully prepared via simple hydrolysis followed by refluxing route in alcohol medium. Several analytic techniques such as XRD, TEM and SEM were used to make characterizations of the as-synthesized samples. The influence of refluxing time on the morphology and average size of the products was investigated. Rod-like doped ZnO powders were easily prepared by refluxing for 5 h. With the elevation of the refluxing time to 20 h, nearly monodispersed sphere-like ZnO nanoparticles can be obtained and the diameter is about 30–50 nm. The results show that refluxing time plays an important role in the formation and oriented growth of ZnO nanocrystals. The powders were consolidated into dense varistors discs by compaction, sintering and evaluated for their electrical characteristics. The varistors can be produced possessing a nonlinear coefficient of ~56, a breakdown voltage of ~7.09 kV/cm.
KeywordsBreakdown Voltage Refluxing Time Polymerize Complex Method Conventional Ball Milling High Voltage Varistor
This work was supported by Changzhou Science, Technology Innovation Project (CC20120031, CC20110048) and Nature Science Foundation of China (No. 51273027) and 2013 Research and Innovation Project for College Graduates.