Dielectric Properties of Surface-Doped Partially Stabilised Zirconia with Ceramic Nanomaterials

The microstructural and dielectric properties of Yttria-partially stabilized zirconia (Y-PSZ) were studied before and after sintering with BaTiO3 and WO3 doping. After sintering, FE-SEM analysis revealed increased grain coalescence and growth, with BaTiO3 causing 300 nm grain expansion and WO3 promoting uniform grain distribution without significant grain size increase (~200 nm). These microstructural changes dramatically altered dielectric behavior. All sintered samples had higher dielectric constants than pre-sintered ones between 100–1000 kHz due to reduced porosity and enhanced homogeneity. Dielectric constant was highest in BaTiO3-doped Y-PSZ at lower frequencies, while WO-doped showed superior frequency stability and lower dielectric loss across the spectrum. In doped crystals, sintering increased crystallinity, lowered defects, and lowered polarization losses. Dielectric loss (tan δ) varied with frequency, with BaTiO3 showing higher losses at low frequencies and showing more stability at higher frequencies, while WO3 showed a moderate, consistent loss. Sintering enhances AC conductivity, especially in BaTiO3-doped materials, via enhancing charge mobility through structural alignment and crystallinity. Due to fault-localized field concentrations, higher voltage increase rates (VIR), lower Weibull modulus and electrical breakdown strength. BaTiO3 and WO3 doping improved grain bonding, void filling, dielectric strength, and energy storage. Tradeoffs between dielectric constant and breakdown strength. High dielectric constants decreased breakdown strength and vice versa. WO-doped Y-PSZ exhibited the highest energy density (22.86 kJ/m3), followed by BaTiO3 (15.22 kJ/m3) and unaltered sintered (14.24 kJ/m3). These investigations demonstrate that alterations to microstructure and the incorporation of impurities improve the energy storage capacity and high-frequency performance of dielectric materials.