High quality crystal growth and characterization of ferroelectric Ba 0. 7 7 Ca 0. 2 3 TiO3single crystal

Abstract

B0.77Ca0.23TiO3 (BCT) single crystal has been widely studied as a promising lead-free ferroelectric material. In this work, high-quality BCT crystal was successfully grown by the Czochralski (CZ) method. The as-grown crystal is crack-free and shows black coloration. It possesses a high dielectric stability over a wide temperature range, while the dielectric loss is rather small below 90∘C. Furthermore, it possesses excellent ferroelectric properties with residual polarization strength (Pr) and coercive field (Ec) of 17.93 μC/cm2 and 8.47 kV/cm, respectively. Besides, BCT crystal shows large electromechanical coupling factors, with kt, k31, k33 and k15 of 0.535, 0.254, 0.714 and 0.721, respectively. The piezoelectric coefficients d31, d33 and d15 are measured to be - 36.5, 130 and 246 pC/N, respectively.