The effect of Li/Ce co‐doping on structural and electrical properties of Sr2−x(Li, Ce)x/2Nb2O7 piezoelectric ceramics

Abstract As a typical perovskite‐like layered structure (PLS) ceramic, Sr 2 Nb 2 O 7 (SNO) possesses a high Curie temperature T C value above 1300°C, which is expected to work in higher temperature environment. However, pure SNO presents a piezoelectric constant d 33 value of ∼ 1 pC/N. Hence, (Li, Ce) ions are doped in SNO ceramics, which increases the distortion of oxygen octahedrons and enhances the intrinsic contribution of piezoelectric properties. The increased domain size with large proportion of high response areas means that the extrinsic contribution is also improved. The introduction of (Li, Ce) ions can also promote ceramic's grain growth and reduce oxygen vacancies, leading to the improvement of electrical properties. The optimal component Sr 1.96 (Li, Ce) 0.02 Nb 2 O 7 ceramics exhibit a d 33 value of 3.1 pC/N, a higher resistivity of 1.65×10 6 Ω·cm at 700°C and an excellent thermal stability (a d 33 value of 3.0 pC/N after annealing at 1200°C for 2 h). This work provides an effective approach with simple process and low cost for the application of PLS materials in high‐temperature environments.