Flux growth and characterization of lead-free piezoelectric single crystal [Bi0.5(Na1−xKx)0.5]TiO3

Lead-free piezoelectric single crystal of [Bi0.5(Na1−xKx)0.5]TiO3 (BNTKx) with size of 10×10×5 mm3 has been successfully grown by the self-flux method. The temperature dependence of dielectric constant was measured and the peak temperature of dielectric constant was found to be 45° higher than that of pure (Bi0.5Na0.5)TiO3 crystal. X-ray diffraction pattern indicated that the BNTK50 crystal is tetragonal (symmetry group 4 mm) with a=b=0.3917nm and c=0.4011nm, respectively. Differential scanning calorimetry showed that the crystal was congruent melting during growth. Superior piezoelectric and electromechanical properties were found in these lead-free crystals.