Enhanced energy storage performance in AgNbO₃ antiferroelectric ceramics via Eu³⁺ substitution

Dielectric capacitors are widely concerned because of high-power density. It is essential to develop lead-free materials with high recoverable energy density (W-rec). Herein, the Ag1-3xEuxNbO3 (AEN(x)) ceramics with x = 0, 0.01, 0.02, and 0.04 were synthesized via a traditional solid-state reaction method. The effects of Eu3+ additions on the phase, microstructure, and energy-storage performance of AgNbO3 (AN) antiferroelectric ceramics were systematically studied. The results show that a few Eu doping do not change the perovskite structure of AN, but reduce the phase-transition temperatures of the monoclinic M1-M2 and M2-M3 phases, as well as the tolerance factor and the grain size. These, in turn, lead to the improved antiferroelectric phase stability and enhanced breakdown strength. Consequently, a large W-rec of 3.32 J/cm(3) and an energy storage efficiency (eta) of 40% were obtained in Ag0.97Eu0.01NbO3 ceramic at an applied electric field of 220 kV/cm, which exhibited satisfactory thermal stability at 30-130 degrees C. Furthermore, the Eu3+ doped ceramics exhibit an excellent practical charging/discharging efficiency (< 60 ns). This work shows that the energy storage performance of AN-based ceramics was significantly optimized by Eu doping, making them competitive candidate materials for pulsed power systems.