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, Ag0.94Eu0.02NbO3 ceramic exhibited a good energy storage density of 5.3 J/cm(3) and a high efficiency of 71.9%. When the temperature rises from room temperature to 140 degrees C, the efficiency of the sample decreases from 80.4% to 67.1% and W-r decreases from 2.1 to 2.0 J/cm(3), 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/cm(3), indicating excellent charge-discharge capabilities. This novel ceramic is expected to be used as a new dielectric capacitor material for pulsed power supplies.