The densification behavior, microstructure, and electrical properties of ZnOhyphen;V2O5ceramics were studied with V2O5as the only additive ranging from 0.01 to 1.0 molthinsp;percnt;. The addition of V2O5to zinc oxide shows a tendency to enhance the densification rate and promote grain growth. However, a microstructure that consisted of anomalously grown grains was found for the specimens containing V2O5ge;0.05 molthinsp;percnt; when sintered at 1100thinsp;deg;C for 2 h. The xhyphen;ray diffraction and SEMhyphen;EDS microanalysis revealed that the sintered specimens had a twohyphen;phase microstructure, i.e., a vanadiumhyphen;rich intergranular phase formed between ZnO grains. The formation of the grain boundary barrier layer was confirmed by the nonhyphen;ohmicIhyphen;Vbehavior and the quick drop of apparent dielectric constant with increasing frequency of the ceramics. A nonlinearity coefficient of 2.4ndash;2.8 was obtained at a current density of 10 mA/cm2for a series ZnOhyphen;V2O5ceramics, and a Schottky barrier height of 0.44ndash;0.47 eV (at 25thinsp;deg;C) was determined from theIhyphen;VandChyphen;Vexperimental data, based on the thermionic emission theory, and the model of backhyphen;tohyphen;back double Schottky barriers.
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