Microstructures and dielectric properties of Ba0.4Sr0.6TiO3 ceramics with BaO-TiO2-SiO2 glass-ceramics addition

The Ba0.4Sr0.6TiO3 energy storage ceramics with BaO-TiO2-SiO2 glass-ceramics additive were prepared via the solid state reaction route. The effects of glass-ceramics content on the sintering behavior, crystal structure, microstructure, dielectric property and energy storage property of Ba0.4Sr0.6TiO3 ceramics have been investigated. SEM-EDX spectra reveal that the glass phase in the BaO-TiO2-SiO2 glass-ceramics existed at grain boundary as liquid phase resulting in the decrease of sintering temperature. XRD results show that Ba0.4Sr0.6TiO3 ceramics exhibited a perovskite structure and emerged the secondary phase BaTi2Si2O8 from the crystal phase in the BaO-TiO2-SiO2 glass-ceramics. The ferroelectrics crystal phase BaTi2Si2O8 increased the dielectric constant of BaO-TiO2-SiO2 glass-ceramics, which inhibited the decrease of dielectric constant of Ba0.4Sr0.6TiO3 ceramics with BaO-TiO2-SiO2 glass-ceramics addition. The breakdown strength was notably improved due to the reduction of the grain size and the samples with 9 wt% glass-ceramics addition showed the highest average breakdown strength of 16.51 kV/mm, which was 1.8 times higher than that of pure Ba0.4Sr0.6TiO3 ceramics. The energy storage density of samples with 5 wt% glass-ceramics addition was 0.6045 J/cm(3) attributed to the relatively high dielectric constant and breakdown strength. (c) 2013 Elsevier B.V. All rights reserved.