Electric field compensation effect driven strain temperature stability enhancement in potassium sodium niobate ceramics

Abstract In view of unsolved key scientific problems of (K,Na)NbO3 (KNN)-based ceramics, this work focuses on intrinsic structure elucidation and physical mechanism of temperature stability in both piezoelectricity d33 and strain property d33* through domain strategy and crystal structure engineering. The introduction of BiFeO3 into KNN-BNH can stabilize multiphase coexistence structure and then results in high performance (d33=400–450 pC/N, TC=280–320 °C, and Suni=0.16–0.18%) with composition in-sensitivity (x = 0–0.6%). Different from the viewpoint of electric field induced diffuse phase transition, we first verified that electric field compensation effect can greatly offset the negative effects induced by polycrystalline phase transition and thermal depolarization, leading to much better temperature stability of d33* than that of d33. We believe that this work has clarified the origin of the difference in temperature stability between d33 and d33*, which can provide some useful clues for further improving the stability of KNN-based ceramics, especially d33 temperature stability for sensor and transducer applications.