Effects of LiNbO3 doping on the microstructures and electrical properties of BiScO3–PbTiO3 piezoelectric system

Piezoelectric ceramics x LiNbO 3 – y BiScO 3 –(1− x − y )PbTiO 3 (LN–BS–PT, 0.00 ≤  x  ≤ 0.10, 0.30 ≤  y  ≤ 0.36) were synthesized and their phase diagram and morphotropic phase boundary between rhombohedral and tetragonal phases have been confirmed. The optimal properties were found at the composition of 0.03LN–0.36BS–0.61PT with piezoelectric coefficient d 33 * value of 702 pm/V, d 33 of 551 pC/N, planar electromechanical coupling factor k p of 0.51, remnant polarization P r of 46.5 µC/cm 2 , Curie temperature T c of 337 °C, and a large strain of 0.351% at an electric field of 50 kV/cm and frequency of 2 Hz with a low strain hysteresis of 5.9%. The Curie temperature of the ternary system presents a linear relationship with LiNbO 3 and BiScO 3 contents. The optimization of these electric properties was probably ascribed to the enhancement in domain walls and the improving mobility of domain switching due to LiNbO 3 doping.