Microstructure and Dielectric Properties of ZnO-SiO2-NiO Composite

The effect of SiO2 addition on the properties of ZnO-NiO composite were investigated. The samples with different SiO2 concentrations were fabricated by the conventional ceramic method and sintered at 10000C The results of XRD show that Zn2SiO4 and Ni2SiO4 generate during sintering, The relative density for the samples increased as the NiO content increased, also it decreased as the SiO2 content increased. The presence of 0.1 wt % ZrO2 remained as chemically stable second phase particles among ZnO grains, and thus retarded densification and inhibited the grain growth of ZnO in the liquid phase sintering. The AC resistivity decreases with increasing frequency at room temperature.