Enhanced energy storage properties of silver niobate antiferroelectric ceramics with A-site Eu³⁺ substitution and their structural origin

AgNbO₃ (AN)-based lead-free antiferroelectric ceramics are widely studied for their use as dielectric capacitor materials. In this study, Eu³⁺-doped AN ceramics were prepared and the results show that Eu³⁺ diffused into the AN lattice. The ceramics were formed by M1 and M2 phases coexisting at room temperature, as distinct from the M1 (M: monoclinic) phase of pure AN. Electrical properties and structural characterization showed that the antiferroelectric stability of the ceramics increases with the increase in Eu³⁺ levels. At room temperature, Ag_0.94Eu_0.02NbO₃ ceramic exhibited a good energy storage density of 5.3 J/cm³ and a high efficiency of 71.9%. When the temperature rises from room temperature to 140 °C, the efficiency of the sample decreases from 80.4% to 67.1% and W_r decreases from 2.1 to 2.0 J/cm³, which indicates that the sample has good temperature stability. The time constant (t_0.9) of this sample was less than 60 ns and the power density (P_D) was 51.3 MW/cm³, indicating excellent charge-discharge capabilities. This novel ceramic is expected to be used as a new dielectric capacitor material for pulsed power supplies.