Crystal growth and characterization of new high Curie temperature (1-x)BiScO₃-xPbTiO₃ single crystals

Novel perovskite ferroelectric (1-x)BiScO₃-xPbTiO₃ single crystals with tetragonal phase were successfully grown by a conventional high-temperature solution method using a Pb₃O₄ and Bi₂O₃ flux. The typical crystal size was 2-15 mm with rectangular shape and green/blue color. The dielectric constant (K) at room temperature was determined to be 400-550, decreasing to about 300 after the poling process. The Curie temperature of 0.43BiScO₃-0.66PbTiO₃ single crystals was found to be about 460°C, similar to the polycrystalline data. The remanent polarization (P(r)) was 28 μC/cm² with a coercive field (E(c)) of 34 kV/cm. The piezoelectric coefficient d₃₃ was about 200 pC/N for 〈0 0 1〉-oriented tetragonal crystals. The longitudinal electromechanical coupling coefficient k₃₃ was ∼ 73% with a lateral mode coupling coefficient k₃₁ of ∼ -35.8% and a thickness mode coupling k(t) of 60-64%.