A peculiar temperature-stable piezoelectric performance and strong self-poling effect was observed in tetragonal phase ferroelectric single crystals 0.38Bi(Mg1/2Ti1/2)O3–0.62PbTiO3. The piezoelectric coefficient d33 of the as-prepared sample with self-poling is 158 pC N−1, and it is as high as 75% of the value produced by an external electric field. The internal electric field Ei exists and the value is 4.34 kV cm−1 at the applied electric field of 40 kV cm−1. The defect dipoles pin on the ferroelectric domains and stabilize the piezoelectric properties and the piezoelectric coefficient d33 at room temperature is nearly unchanged until the annealing temperature up to 800 °C, which is much higher than the Curie temperature Tc ∼ 520 °C.

•Novel perovskite ferroelectric 0.63BMT–0.37PT single crystals near the morphotropic phase boundary were successfully grown by a self-flux method.•The 0.63BMT–0.37PT single crystals presented high Curie temperature (Tc) about 460 °C and a rhombohedral to tetragonal phase transition temperature (Tr-t) 249 °C.•The d33 of 0.63BMT–0.37PT single crystals is 320pC/N, much higher than that of ceramics with the same composition (220pC/N).Novel perovskite ferroelectric 0.63Bi(Mg1/2Ti1/2)O3–0.37PbTiO3 (0.63BMT–0.37PT) single crystals with a composition around the morphotropic phase boundary (MPB) were successfully grown by a self-flux method. They presented Curie temperature (Tc) about 460 °C and a rhombohedral to tetragonal phase transition temperature (Tr-t) 249 °C. The piezoelectric constant d33 for (001) oriented 0.63BMT–0.37PT single crystals reached 320pC/N, which was higher than that (208pC/N) in the tetragonal phase 0.38BMT–0.62PT crystals. The large piezoelectric constant d33 and high Tc make BMT–PT single crystals promising candidates used for the next generation of high performance and high temperature actuators and transducers.

Novel ferroelectric single crystals 0.38Bi(Mg1/2Ti1/2)O3–0.62PbTiO3 have been successfully grown by a flux method. The Tc and d33 are 520 °C and 208 pC N−1, respectively. Good temperature stability, together with good piezoelectric properties and high Tc make the single crystals promising novel piezoelectric materials for high-temperature, high-performance actuators and transducers.

Lead-free solid solution crystals (Na, Bi)TiO3–BaTiO3 [NBBT] and (K,Na)NbO3–LiNbO3[KNN–LN] have been grown by the Bridgman method. Their piezoelectric constant d33 reach 160 and 405 pC/N, respectively. Domain dynamics shown through in-situ observation using a polarizing microscopy in 0.94NBT-0.06BT crystals demonstrate that both of ferroelectric–antiferroelectric phase transition and antiferroelectric–paraelectric one take place in broad temperature ranges. 0.94NBT-0.06BT is more relaxor ferroelectric whereas 0.95KNN-0.05LN crystal is more normal ferroelectric. Moreover, it is found that the ferroelectric phase coexists with the paraelectric phase at the temperature much higher than their Curie temperature in both crystals. The low value of d33 may originate from the existence of an antiferroelectric tetragonal phase in a ferroelectric rhombohedral phase in NBBT crystals.