Improved dielectric strength and energy storage density in Ba6−3xLa8+2xTi18O54 (x = 0.5, 2/3, and 0.75) ceramics

Abstract Dielectric strength and energy storage density in Ba 6−3 x La 8+2 x Ti 18 O 54 ( x = 0.5, 2/3, and 0.75) ceramics were investigated as functions of composition and microstructure. With increasing x , although the dielectric constant decreased from 113 to 102, the energy storage density increased from 2.3 J/cm 3 to 3.2 J/cm 3 due to the increased dielectric strength for ceramics prepared by conventional sintering. The energy storage was further improved to 4.2 J/cm 3 in ceramics prepared by spark plasma sintering under an electric field of 1058 kV/cm. Both dielectric strength and energy storage density in the present ceramics indicated the strong processing and microstructure dependence. The optimum dielectric strength and energy storage density were achieved in the dense ceramics with fine grains, while both dielectric strength and energy storage density decreased in the ceramics with coarse columnar grains.