Less temperature-dependent high dielectric and energy-storage properties of eco-friendly BiFeO3-BaTiO3-based ceramics

The effects of eco-friendly (BiNa0.K-84(0.16))(0.48)Sr0.04TiO3 (BNKS)-content in 0.65Bi(1.05)FeO(3)-0.35BaTiO3 (BFBT) dielectrics were investigated by following simple solid state fabrication route. By the introduction of BNKS in BFBT matrix the average grain size was significantly reduced, with relatively high dense microstructure (relative density > 94%). The BNKS-modified BFBT dielectrics demonstrated thermally-stable epsilon(r) (670-1005, from 30 degrees C to 500 degrees C), high T-max (424 degrees C-465 degrees C), colossal epsilon(r-max) (58880-69226), and epsilon(r-mid) (2891-5652 +/- 15%) across the broad range of temperature from 244 degrees C to 500 degrees C. At the optimum composition (x = 0.10) the temperature-dependent (30 degrees C-150 degrees C) substantially high energy-storage density (W-store similar to 0.81 J/cm(3)) and efficiency (eta > 60%) in bulk ceramics were observed. The thermally-stable dielectric and energy storage properties suggest that present investigated dielectrics can be promising candidates for high temperature dielectric applications and power electronics. (C) 2019 Elsevier B.V. All rights reserved.