Piezoelectric applications of hydrothermal lead-free (K<inf>0.48</inf>Na<inf>0.52</inf>)NbO<inf>3</inf> ceramics

Abstract

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 KNbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> and NaNbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> powders, a high-dense lead-free piezoelectric (K,Na)NbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ceramics could be obtained (density: 98.8%). Concerning about the g <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">33</sub> constant, high value as large as commercial PZT ceramics was measured. Therefore, the hydrothermal (K,Na)NbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ceramics is usable for the sensors and the energy harvesting devices. To demonstrate the (K,Na)NbO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> ceramics, a hydrophone sensor was fabricated and evaluated.