Enhanced energy storage density and its variation tendency in CaZrxTi1−xO3 ceramics

The improved energy storage density and its variation tendency have been investigated for CaZrxTi1−xO3 (x = 0.0, 0.1, 0.2, 0.3, 0.4, 0.5) solid solution ceramics. The dense ceramics with high bulk density above 97% could be obtained, and X-ray diffraction analysis confirms the orthorhombic single phase structure in all compositions. Substitution of Zr4+ obviously increases the sintering temperature, and the homogeneous fine grain structure is obtained. With increasing x, the dielectric constant εr decreases from 175 to 103, while the dielectric strength Eb increases from 435 kV/cm to 756 kV/cm. The highest energy storage density of 2.7 J/cm3 is achieved at x = 0.4, which is much higher than that of CaTiO3 end-member. The energy storage density significantly increases with decreasing the thickness due to the increased dielectric strength (For the samples with x = 0.5, the dielectric strength increases from 584 kV/cm to 756 kV/cm while the energy storage density increases from 1.6 J/cm3 to 2.6 J/cm3 when the thickness changes from 0.50 mm to 0.15 mm).