Structure and dielectric/piezoelectric properties of LiNbO3-doped BiScO3–PbTiO3 ceramics with morphotropic phase boundary composition

0.02LiNbO3–0.98{(1 − x)BiScO3–xPbTiO3} (2LN–BS–xPT) ceramics near the morphotropic phase boundary (MPB) were investigated. MPB region of 2LN–BS–xPT ceramics was identified to be in the composition of 0.62 < x ≤ 0.64. The coexistence of the tetragonal domain structure and a polar microdomain structure was observed by transmission electron microscope for x = 0.64. It is found that 2LN–BS–xPT ceramics (x = 0.64) showed good piezoelectric and ferroelectric properties with piezoelectric constant d33 about 505 pC/N, planar electromechanical coupling factors kp about 0.47, and remnant polarization Pr about 40 μC/cm2, respectively, while Tmax is about ~350–400 °C. The high-temperature relaxation behavior was also studied in 2LN–BS–xPT ceramics. Effects of thermal depoling on the piezoelectric properties of 2LN–BS–xPT ceramics indicated good thermal stability before 300 °C for x = 0.62 and 0.64.