Investigation on the phase transition behavior and electrical properties of textured Lix(K0.48Na0.52)1−xNbO3 piezoelectric ceramics

Lead-free Lix(K0.48Na0.52)1−xNbO3 (KNN-xLi) ceramics were successfully prepared by the tape casting method and solid-state reaction. The effects of Li content on phase transition, microstructure and electrical properties were investigated. XRD results show strong preferred orientation, indicating the presence of textured structure in the samples. With increasing Li content, the Currie Temperature shifts to higher temperature while the phase transition temperature between orthorhombic and tetragonal phases shifts to lower temperature. The sample with x=0.05 is determined to contain two perovskite phases with orthorhombic and tetragonal structures at room temperature, respectively, and exhibits the maximum values of piezoelectric coefficient of 286 pC/N and planar electromechanical coupling factor of 0.45.