Effects of NaNbO<inf>3</inf>crystals on electrical properties of K<inf>0.5</inf>Na<inf>0.5</inf>NbO<inf>3</inf>ceramics

Abstract

© 2016 Trans Tech Publications, Switzerland. Lead-free (K0.5Na0.5)NbO3(KNN) piezoelectric ceramics were studied and synthesized by the seed-induced method. NaNbO3crystal was used as the seed and was prepared by molten salt synthesis (MSS). The average particles size of the NaNbO3seed crystal was about 1-3 ìm. Then, the NaNbO3seed was mixed with KNN powder and ball milled for 24 h. The mixed powder was calcined at 700-900 °C and sintered at 1100 °C. The phase structure and morphology of the ceramics were investigated by X-ray diffraction and scanning electron microscope and the electrical properties were measured. The results indicated that all samples showed a pure perovskite phase. The highest density of the ceramic was 93% compared to the theoretical density. The results showed that NaNbO3seed crystal improved the piezoelectric properties of KNN ceramics.