Core-shell BaTiO3@BiScO3 particles for local graded dielectric ceramics with enhanced temperature stability and energy storage capability

Core-shell BaTiO 3 @BiScO 3 (BT@BS) particles were fabricated via a facile sol-precipitation method, with which bulk ceramics were prepared via conventional sintering. Pure perovskite phases of the BT@BS ceramics were confirmed by XRD patterns. Grain sizes and DC conductivities of the BT@BS ceramics are suppressed in comparison with pure BT. Dielectric-temperature measurements show that with the addition of BS, the tetragonal-orthorhombic and orthorhombic-rhombohedral peaks sequentially disappear with gradual broadening and dispersion of Curie peaks. Wide and flat dielectric-temperature plateau is achieved in the ceramic with 3 mol% BS coatings, which is due to the formation of local compositionally graded structure from the modulated diffusion of Bi and Sc. Weakened polarization nonlinearity and reduced hysteresis are achieved in the BT@BS ceramics, which contribute to enhanced energy storage capability. This work provides a generic avenue for fabricating temperature-stabilized dielectrics with improved energy storage density.