Dielectric temperature stability and energy storage performance of B-site Sn4+-doped BNKBST ceramics

The 0.65Bi(0.5)Na(0.25)K(0.25)TiO(3)-0.35Bi(0.2)Sr(0.7)Ti(1-x)Sn(x)O(3)(BNKBST-xSn) ceramics were synthesized via a solid-phase reactive sintering technique. The effects of doping Sn(4+)ions on the energy storage, dielectric, ferroelectric properties and microstructure characteristics for BNKBST ceramics were systematically studied. Remarkably, BNKBST-0.02Sn exhibits a superior dielectric temperature stability, manifested as the change rate for dielectric constant increment epsilon/epsilon(150 degrees C)is smaller than 15% during a very wide temperature range of 30-400 degrees C. In addition, BNKBST-0.02Sn ceramic achieves a high energy storage densityW(rec) = 0.81 J/cm(3)(under the electric field 80 kV/cm) with an outstanding energy storage efficiency 89.5%, which make it reasonable to be applied in dielectric capacitors due to its excellent dielectric thermal stability and energy storage properties. The electrical conductivity behaviors of BNKBST-xSn were also analyzed with the assistance of impedance spectroscopy.