Improvement in dielectric properties and energy storage performance of barium strontium niobate glass ceramics by Sm2O3 addition

Abstract

High power density and high energy density glass ceramics have important applications in the field of miniaturized, lightweight and integrated pulsed power devices. Barium strontium niobate glass ceramics with different additive amount of Sm2O3 were successfully prepared. The effects of different additions of Sm2O3 on the phase composition, dielectric properties, breakdown strength, interfacial polarizations and energy storage properties of glass ceramics were investigated. The results of phase structure show that Ba0.5Sr0.5Nb2O6 of tungsten bronze structure and BaAl2Si2O8 two phases are precipitated from the glass matrix. The optimum Sm2O3 addition can increase the Ba0.5Sr0.5Nb2O6 phase content of tungsten bronze structure in the glass ceramics, thus increasing the dielectric constant of strontium barium niobate glass ceramics. A moderate amount of Sm2O3 addition improves the microstructure of the barium strontium niobate glass ceramics and reduces the interfacial activation energy of the glass ceramics, thus increasing the breakdown strength of the glass ceramics. For 3 mol% Sm2O3 addition, the breakdown strength of the glass ceramics reaches 1590 kV/cm with a corresponding dielectric constant of 98.4 and a maximum energy storage density of 12.44 J/cm3, which is 2.62 times higher than that of the barium strontium niobate glass ceramics without Sm2O3 addition. It is concluded that the increased energy density of glass ceramics can be attributed to the fact that the appropriate additive amount of Sm2O3 (1–3 mol%) increases the crystallinity of the glass ceramics and at the same time reduces the interfacial activation energy of the glass ceramics, thus increasing the dielectric properties of the glass ceramics with respect to the breakdown strength.