Piezoelectric applications of hydrothermal lead-free (K0.48Na0.52)NbO3 ceramics

A hydrothermal method utilizes a crystallization process in the solution so that the pure and high-quality powders can be realized. Sintering from the hydrothermal KNbO₃ and NaNbO₃ powders, a high-dense lead-free piezoelectric (K,Na)NbO₃ ceramics could be obtained (density: 98.8%). Concerning about the g₃₃ constant, high value as large as commercial PZT ceramics was measured. Therefore, the hydrothermal (K,Na)NbO₃ ceramics is usable for the sensors and the energy harvesting devices. To demonstrate the (K,Na)NbO₃ ceramics, a hydrophone sensor was fabricated and evaluated.