Growth and electrical properties of 0.95Na0.5Bi0.5TiO3-0.05K0.5Bi0.5TiO3 lead-free piezoelectric crystal by the TSSG method

0.95Na(0.5)Bi(0.5)TiO(3)-0.05K(0.5)Bi(0.5)TiO(3) lead-free piezoelectric single crystal with rhombohedral structure was grown by the top-seeded solution growth method. The temperature dependence of dielectric constant and loss, polarization hysteresis loops, the optimum poling condition and the electromechanical coupling property were investigated for the < 100 >-oriented as-grown crystal. The curves epsilon(T) show two anomalies, which are related to the two phase transformations at the temperature range of 130-340 degrees C. The piezoelectric constant d(33) and electromechanical coupling coefficient k(t) for the < 001 >-oriented crystal at room temperature reached 147 pC/N and 0.52, respectively. The value of k(t) demonstrated a relatively stable thermal electromechanical coupling property over the temperature range of 15-130 degrees C. (C) 2011 Elsevier B.V. All rights reserved.