Achieving enhanced ferroelectricity and piezoelectric responses in 〈0 0 1〉-textured KNN-BCZT ceramics with BaTiO3 microplates as template

Abstract

Potassium sodium niobate (KNN) as a typical lead-free piezoelectric ceramic has higher Curie temperature, but its piezoelectric constant is not high enough at room temperature. The introduction of BCZT with high piezoelectric responses into KNN is an important strategy to improve its piezoelectric properties. Moreover, orientation engineering is also a significant method to enhance piezoelectric responses of KNN-based ceramics. Herein, 〈001〉 crystallographic texture in KNN-BCZT ceramics was realized though templated grain growth method with BaTiO3 microplates as template, and the textured sample exhibited superior ferroelectric and piezoelectric properties (2Pr = 43.5μC/cm2, d33*=137 pm/V, d33 = 190 pC/N, kp = 0.54) and lower phase transition temperatures (TO-T = 170.2 °C, TC = 388.3 °C) than randomly oriented sample. This work provides a good strategy to design KNN-based lead-free ceramics with superior piezoelectric properties by constructing solid solution system and controlling crystallographic orientation.