Effect of Bi0.2Sr0.7SnO3 doping on NaNbO3-based ceramics: enhanced ferroelectric, dielectric, and energy storage performance

NaNbO3-based antiferroelectric ceramics are considered to be popular candidates for lead-free dielectric capacitors. However, the instability of the antiferroelectric phase of pure NaNbO3 (NN) ceramics under high electric fields leads to poor energy storage density and efficiency. Therefore, in order to stabilize the antiferroelectric phase of NN, (1 - x)NaNbO3-xBi(0.2)Sr(0.7)SnO(3) [(1 - x)NN-xBSS] (x = 0.06-0.20) system was successfully prepared by the solid-state reaction method. The solid solution transforms from the antiferroelectric phase (AFE) to the paraelectric phase (PE) with increasing BSS doping. In addition, the Curie temperature (T-m) changes abruptly from nearly 250 degrees C to - 120 degrees C at x = 0.10 and exhibits relaxation behavior. The best performance with a recoverable energy density (W-rec) of 0.80 J/cm(3) and efficiency (eta) of 80.2% in this system is obtained simultaneously at 180 kV/cm in the component with x = 0.10. Furthermore, the 0.90NN-0.10BSS ceramic has good frequency stability. This work provides a new doping strategy and systematically investigates phase structure, microscopic morphology, and macroscopic electrical properties of (1 - x)NN-xBSS ceramics.