TY - JOUR AB - (K,Na)NbO3 ceramics have attracted much attention as lead-free piezoelectric materials with high piezoelectric properties. High-quality (K,Na)NbO3 ceramics can be sintered using KNbO3 and NaNbO3 powders synthesized by a hydrothermal method. In this study, to enhance the quality factor of the ceramics, high-power ultrasonic irradiation was employed during the hydrothermal method, which led to a reduction in the particle size of the resultant powders. AU - Isobe, G. AU - Maeda, Takafumi AU - Bornmann, Peter AU - Hemsel, Tobias AU - Morita, Takeshi ID - 9878 IS - 2 JF - Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on KW - Q-factor KW - ceramics KW - crystal growth from solution KW - particle size KW - piezoelectric materials KW - potassium compounds KW - powders KW - sintering KW - sodium compounds KW - ultrasonic effects KW - (K0.48Na0.52)NbO3 KW - KNbO3 powders KW - NaNbO3 powders KW - high-power ultrasonic irradiation KW - lead-free piezoelectric materials KW - lead-free piezoelectric powders KW - particle size reduction KW - piezoelectric properties KW - quality factor KW - sintered (K0.48Na0.52)NbO3 ceramics KW - sintering KW - ultrasonic-assisted hydrothermal method KW - Acoustics KW - Ceramics KW - Lead KW - Piezoelectric materials KW - Powders KW - Radiation effects KW - Transducers SN - 0885-3010 TI - Synthesis of lead-free piezoelectric powders by ultrasonic-assisted hydrothermal method and properties of sintered (K0.48Na0.52)NBO3 ceramics VL - 61 ER - TY - JOUR AB - The hydrothermal method enables the production of high-quality piezoelectric materials. In this study, we propose to irradiate the reaction solutions with ultrasonic power during the hydrothermal method to obtain a shorter reaction time and a smooth film surface. A high-pressure reaction container for the ultrasonic transducer was newly developed, and the ultrasonically-assisted hydrothermal method was examined by using this container. The effect of ultrasonic assist on the synthesis of lead-zirconate-titanate (PZT) thin films and (K,Na)NbO$_{3}$ powders was verified. Thicker PZT film, thickness around 10 ${\mu}$m, could be obtained in one process, and (K,Na)NbO$_{3}$ powder was synthesized in half the previous reaction time. AU - Ageba, Ryo AU - Kadota, Yoichi AU - Maeda, Takafumi AU - Takiguchi, Norihito AU - Morita, Takeshi AU - Ishikawa, Mutsuo AU - Bornmann, Peter AU - Hemsel, Tobias ID - 9743 IS - 4 JF - Journal of Korean Physical Society KW - Hydrothermal method KW - High-power ultrasonic KW - PZT thin film KW - Lead-free piezoelectric materials SN - 1948-5719 TI - Ultrasonically-assisted Hydrothermal Method for Ferroelectric Material Synthesis VL - 57 ER -