The Effect of Zinc Oxide Nanoparticles on the Microstructure and Dielectric Properties of Barium Titanate Ceramics

(1-x) BaTiO3-x ZnO ceramics with x values of 0, 0.5, 1, and 2 wt. % were prepared using the solid-state method. The effect of adding zinc oxide nanoparticles on the densification, microstructure, and dielectric properties of barium titanate ceramics was investigated. Barium titanate powder was synthesized at a temperature of 1200 °C using the solid-state method. The samples were then prepared by pressing and sintered at 1280 °C. The addition of 2 wt. % zinc oxide nanoparticles increased the density of the barium titanate ceramics from 93.5 % to 98.2 % and reduced the porosity from 6.5 % to 1.8 %. The samples containing zinc oxide nanoparticles exhibited a dense microstructure with grain growth. An increase in the content of zinc oxide nanoparticles led to a decrease in the dielectric constant and dielectric loss (tangent delta) of the barium titanate ceramics. The sample containing 2 wt. % zinc oxide nanoparticles revealed the lowest dielectric constant value. At a frequency of 1 kHz, the dielectric constant of barium titanate decreased from 1745 to 895 for the sample containing 2 wt. % zinc oxide nanoparticles. The dielectric loss of the samples containing zinc oxide nanoparticles at high frequencies (above 1 kHz) were all around 0.025, which showed a significant reduction compared to the dielectric loss of barium titanate ceramics (around 0.065). The addition of 1 wt. % zinc oxide nanoparticles caused a decrease in the remnant polarization of barium titanate from 3.7 μC/cm² to 1.2 μC/cm². The coercive field for these samples was measured to be around 3.3 kV/cm.