Dielectric properties of A and B-site doped BaTiO3-based high-entropy ceramics prepared by fast hot-pressing sintering

In order to further improve their dielectric properties of BaTiO3-based high-entropy ceramics, three groups of perovskite-structured high-entropy dielectric ceramics with compositions of (Ca1/3Sr1/3Ba1/3)(Ti1/3X1/3Y1/3)O3 (X and Y chosen from Zr, Hf, and Sn) were fabricated by solid state reaction method and then fast hot-pressing sintering (FHPS) at 1300 °C and 50 MPa. All three groups of samples possess a single-phase perovskite structure with an average grain size of 160–727 nm and a uniform elemental distribution. Among the three groups of samples, (Ca1/3Sr1/3Ba1/3)(Ti1/3Sn1/3Hf1/3)O3 exhibits the highest dielectric constant of 11,037 at the Curie temperature of 588 °C, while (Ca1/3Sr1/3Ba1/3)(Ti1/3Zr1/3Hf1/3)O3 shows the highest discharge energy storage density (Wd = 0.702 J/cm3) and the critical electric field (CEF = 389 kV/cm) corresponding to the saturation polarization intensity. The CEF and energy storage performance of the three samples are significantly higher than those of BaTiO3 (Wd = 0.08 J/cm3, η = 46.09%, CEF = 30 kV/cm) and other reported BaTiO3-based high-entropy ceramics.