Dielectric relaxation behavior and energy storage properties in SrTiO3 ceramics with trace amounts of ZrO2 additives

SrTiO3 ceramics with trace amounts of ZrO2 additives were prepared via the solid state reaction route. The effects of ZrO2 concentrations on microstructures, dielectric and energy storage properties of SrTiO3 ceramics were investigated. The grain size of the ceramics decreases with increasing ZrO2 concentration. Dielectric relaxation behaviors were observed in dielectric loss versus temperature plots and studied by the measurements of the activation energies, which indicated the behaviors were due to the doubly ionized oxygen vacancies and the space-charge polarization. An energy density of 1.62 J/cm3 and a breakdown strength of 289 kV/cm were achieved for SrTiO3 ceramics with 0.4 mol% ZrO2 addition, which were higher than those of pure SrTiO3 ceramics.