Investigation of zinc oxide additive on the dielectric properties and microstructure of titanium oxide ceramic

In recent years, research into materials with high dielectric constants, including doped titanium oxide, has increased because of the potential for modern microelectronics applications and high-density energy storage. The aim of this study was to investigate the effects of zinc oxide as an acceptor additive on the dielectric properties and microstructure of titanium oxide ceramics. The amount of 0.5, 1 and 2 wt% of the additive was added to the titanium oxide and the samples were prepared by powder pressing method and then sintered at 1420 ºC for 5 hours. The properties of the samples including density, phases, dielectric constant, dielectric loss and microstructure were investigated. The results showed that zinc oxide improved the density of titanium oxide. The results of X-ray diffraction test showed that there was no secondary phase and impurities in the samples containing the additive, which could indicate the replacement of the additive in the crystalline lattice of titanium oxide and the formation of a solid solution. The addition of zinc oxide resulted in the decreasing of dielectric constant and dielectric loss of titanium oxide. Zinc oxide additive caused grain growth and increase of grain size of titanium oxide ceramic. Microstructures with very large grain sizes and the possibility of creating oxygen vacancy with using zinc oxide additives can lead to the reduction in the dielectric constant of the titanium oxide ceramic.