Crystallization kinetics behaviour and dielectric properties of strontium barium niobate-based glass-ceramics

摘要

Strontium barium niobate-based glass-ceramics (SBN-glass-ceramics) with various B_2O_3/SiO_2 ratios have been prepared by powder-melting method followed by controlled crystallization. The effects of different B_2O_3/ SiO_2 ratios on the phase evolution, microstructure, dielectric property, breakdown strength and energy storage density of the SBN-glass-ceramics were studied. In addition, the crystallization kinetics behavior of the SBN-glass was analyzed by differential scanning calorimeter method. The microstructure of the SBN-glass-ceramics by replacing SiO_2 with B_2O_3 becomes dense and uniform dramatically. Through the analysis of the crystallization kinetics, replacing a small amount of SiO_2 with B_2O_3 can make the SBN-glass less stable, which is conducive to crystallization in the SBN-glass. When the ratio of B_2O_3/SiO_2 is 1.5/ 33.5 in the SBN-glass-ceramics, the dielectric constant is up to 143.2 and the optimized theoretical energy storage density of 7.4 J/cm~3 is achieved at room temperature, which is about 2 times higher than that of the boron-free SBN-glass-ceramics.