A tunable B-site doping SBT-BNT-SMN ceramic composite with high recoverable energy density and temperature stability

We synthesize a group of three-phase ferroelectric ceramics 0.35(Sr 0.7 Bi 0.2 ) TiO 3 –0.65(Bi 0.5 Na 0.5 )TiO 3 –xSr(Mg 1/3 Nb 2/3 )O 3 (BST–BNT–xSMN) using conventional solid-phase sintering method. When tunning the volume of SMN to 0.01, the ceramic sheet shows homogeneous microcrystal grains and highly dense crystal morphology, which favors a reductive dielectric permittivity ( ε r ) of 2250 and loss of 0.05. Under a high electric field of 100 kV cm −1 , the BST–BNT- 0.01 SMN sample achieves a slender polarization versus electrical field (P–E) loop with saturation and residual polarization of 37.1 µC cm −2 and 3.0 µC cm −2 , respectively, corresponding to a high energy density of 1.32 J cm −3 and a large η of 81%. Strikingly, the BST–BNT–xSMN ceramics show the excellent temperature stability below 100 °C, which facilitates energy storage in relaxed ferroelectric ceramics and provides an efficient method for obtaining pulsed power capacitors with excellent energy-recoverable characteristics and high efficiency in BNT-based ceramics. Graphical abstract The three-phase ferroelectric ceramics 0.35(Sr 0.7 Bi 0.2 )TiO 3- 0.65(Bi 0.5 Na 0.5 )TiO 3- xSr(Mg 1/3 Nb 2/3 )O 3 (BST- BNT- xSMN) possesses a slender polarization versus electrical field loop with saturation and residual polarization of 37.1 µC cm -2 and 3.0 µC cm -2 respectively at 100 kV cm -1 , which corresponds to a high energy density of 1.32 J cm -3 and a large η of 81%.