(K0.5Na0.5)NbO3 based lead free piezoelectrics with expanded temperature usage range

Lead free materials 0.95(K0.5Na0.5)NbO3-0.05LiSbO3 modified by CaTiO3 (CT) (1??3wt%) have been synthesized by conventional sintering. All samples exhibited pure perovskite phase with a tetragonal structure at room temperature. The Curie temperature was found to decrease with increasing CT addition in KNN-LS ceramics, while the orthorhombic to tetragaonl polymorphic phase transition was found to shift further downward from room temperature to lower than ??50??C, expanding the temperature usage range. The piezoelectric coefficient d31 and electroemchanical coupling factor k31 for CT (1wt%) modified KNN-LS materials were found to be on the order of ??90pC/N and ??28.5% at room temperature, respectively, comparable to those values of pure KNN-LS. Together with its broadened temperature usage range, makes the CT modified materials promising candidates for sensor and transducer applications.