Excellent energy-storage properties of NaNbO3-based lead-free antiferroelectric orthorhombic P-phase (Pbma) ceramics with repeatable double polarization-field loops

The energy-storage performance of stable NaNbO3-based antiferroelectric (AFE) ceramics was for the first time reported in (0.94-x)NaNbO3-0.06BaZrO(3)-xCaZrO(3) lead-free ceramics. A gradual evolution from an instable AFE phase (x <= 0.01) to an orthorhombic AFE P phase (Pbma) (0.01 < x <= 0.05) was found to accompany the appearance of repeatable double-like polarization versus electric field loops although poled samples (x < 0.01) own an AFE monoclinic phase (P2(1)). Interestingly, compared with x <= 0.01 samples with instable anti-ferroelectricity, a relatively high recoverable energy storage density W-rec (similar to) 1.59 J/cm(3) (@ 0.1 Hz) and a storage efficiency eta of (similar to)30% were achieved in the x = 0.04 ceramic. Moreover, a high W-rec of > 1.16 J/cm(3) and an outstanding charge-discharge performance with fast discharge rate (t(0.9) < 100 ns) were generated in the temperature range from room temperature to 180 degrees C in the x = 0.04 ceramic. These results suggest that NaNbO3-based AFE P-phase ceramics could be new potential dielectric materials for high-energy storage capacitors.