Dielectric and Energy Storage Property of (0.96NaNbO3-0.04CaZrO3)-xFe2O3 Antiferroelectric Ceramics

0.96NaNbO(3)-0.04CaZrO(3) (NNCZ) ceramic shows stable double hysteresis loops at room temperature, but the property of energy density, energy storage efficiency and breakdown strength of NNCZ are terrible, which limit NNCZ to be used as energy storage materials. In this work, Fe2O3 was chosen to modify the energy storage property of NNCZ. (0.96NaNbO(3)-0.04CaZrO(3))-xFe(2)O(3) (NNCZ-xFe) antiferroelectric ceramics were prepared by traditional solid reaction method. The phase, morphology, dielectric property and energy storage property of NNCZ-xFe were characterized. The results indicated that the crystal structures of NNCZ-xFe ceramics were pure perovskite structure. The sintering temperature of NNCZ ceramic was decreased with addition of Fe2O3. With the increase of Fe2O3 content, the grain size of NNCZ-xFe were decreased firstly and then raised. The NNCZ-0.02Fe ceramic obtained the smallest grain size (5.04 mu m) and the best energy storage property. The breakdown strength of NNCZ-0.02Fe was 230 kV/cm at room temperature (RT). The recoverable energy density and energy storage efficiency before breakdown were 1.57 J/cm(3) and 55.74% respectively. At 125 degrees C and 180 kV/cm, the energy density of NNCZ-0.02Fe was 4.53 J/cm(3). Fe2O3 doping decreased the sintering temperature of NNCZ ceramics, reduced the the migration rate of oxygen vacancies and inhibited the growth of grains. At the same time, it reduced the dielectric loss and improved the breakdown strength. The oxygen vacancies pinning made antiferroelectric phase switch to ferroelectric phase harder, avoided appearance dumbbell-shaped double hysteresis loops, so the energy storage efficiency was improved. This research shows that NNCZ-xFe has a good potential application in the field of dielectric energy storage.