Papers by Keyword: ZnO Ceramics

Abstract: The compositions, electrical properties and microstructures of zinc oxide ceramics with various 46.6ZnO-20Na₂O-33.4P₂O₅ glass oxide additions prepared by solid-state method have been investigated. The structure of the materials is studied using X-Ray diffraction, and the microstructure is analyzed using scanning electron microscopy. The results indicated that the electrical properties were associated with the amount of 46.6ZnO-20Na₂O-33.4P₂O₅ glass oxide additions and the sintering temperatures. The correlation between the microstructures, oxide additions and the sintering temperature was also discussed. From the results of electrical properties measurements, zinc oxide ceramics with various 46.6ZnO-20Na₂O-33.4P₂O₅ glass oxide additions exhibits a good electrical behavior, which can be a suitable candidate material for electronic device applications.

Abstract: ZnO ceramic samples with the chemical formula, 97ZnO-2BaO-1(X)Mol% (where X= CuO, Fe2O3, TiO2, V2O5, MoO3) have been prepared by using conventional ceramics techniques. The samples were sintered at 1200°C for 1, 1.5 or 2h. The metal ions were chosen such that their ionic radii were just slightly different, whereas their ion valences varied from 2+ in case of Cu to 6+ for Mo. Room-temperature I-V characteristics, microstructures, linear scans and X-ray patterns were then studied. The microstructure and linear scan data revealed that, in the case of Cu-, Fe-, V- and Mo-doped ceramics, the doped ions resided mainly at the grain boundaries while, in case of Ti-doping, the ions resided mainly in the grain interior. The electrical measurements and the linear scan data showed that both the non-linearity parameter, α, and the rate of change of α with sintering time, (dα/dt), was exponentially proportional to the valence of the doped ion, where t is a sintering time in the range of 1 to 2h. The leakage current, JL, is linearly proportional to the amount of doped ion present in the grain interior, relative to that present at the boundaries. The X-ray data revealed that the obtained phase was the hexagonal ZnO phase, with traces of secondary phase related to the doped ion; the secondary phases were identified as being Fe2O3, BaTi5O11, Zn3(VO4)2 and (ZnMoO4) in case of Fe-, Ti-, V- and Mo-doped ceramics, respectively. The relative intensity of the X-ray peak at 2θ = 34.45, corresponding to the (0002) plane, was exponentially proportional to the valence of the doped ion; while α scaled with the relative intensity of the aforementioned X-ray peak.