Growth and properties of Li, Ta modified (K,Na)NbO3 lead-free piezoelectric single crystals
Li, Ta modified (K,Na)NbO3 single crystals with the size of 18 mm x 18 mm x 10 mm were successfully grown by top-seeded solution growth method, with orthorhombic-tetra-gonal phase transition temperature ∼79 °C and Curie temperature ∼276 °C. The electromechanical coupling factors k33 and kt were found to be ∼88% and ∼65%, respectively. The piezoelectric coefficient d33 for the c poled crystals reached 255 pC/N. In addition, the electromechanical coupling factor exhibited high stability over the temperature range of -50 °C to 70 °C, making these lead free crystals good candidates for electromechanical applications. 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.