Phase composition, microstructure, and dielectric properties of dysprosium-doped Ba(Zr0.1Ti0.9)O3-based Y5V ceramics with high permittivity

Barium zirconium titanate, Ba(Zr0.1Ti0.9)O3, nanopowders modified with zinc (Zn), niobium (Nb), and dysprosium (Dy) were synthesized by a sol-gel process. The relationships among the phase compositions, microstructures, and properties of sintered ceramics were investigated. The microstructural investigation showed that the grain size of Ba(Zr0.1Ti0.9)O3-Zn-Nb ceramics was in the range 30-3 μm when the Dy content increased from 0.0 to 0.6 mol%. Average grain size of the ceramics decreased with increasing concentration of Dy; however, the maximum dielectric constant (εmax) first increased and then decreased. Using a modified version of the Curie-Weiss law, a critical exponent (γ) was calculated. When the Dy concentration was 0.4 mol%, the γ coefficient for the sample equaled approximately 1.43, which confirms that the material shows relaxor behavior. Our results show that these materials met the Electronic Industries Alliance Y5V specifications and that εmax was higher than 20,000, with a dielectric loss (at 25 °C) of only 0.006.