@article{9878,
  abstract     = {{(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.}},
  author       = {{Isobe, G. and Maeda, Takafumi and Bornmann, Peter and Hemsel, Tobias and Morita, Takeshi}},
  issn         = {{0885-3010}},
  journal      = {{Ultrasonics, Ferroelectrics, and Frequency Control, IEEE Transactions on}},
  keywords     = {{Q-factor, ceramics, crystal growth from solution, particle size, piezoelectric materials, potassium compounds, powders, sintering, sodium compounds, ultrasonic effects, (K0.48Na0.52)NbO3, KNbO3 powders, NaNbO3 powders, high-power ultrasonic irradiation, lead-free piezoelectric materials, lead-free piezoelectric powders, particle size reduction, piezoelectric properties, quality factor, sintered (K0.48Na0.52)NbO3 ceramics, sintering, ultrasonic-assisted hydrothermal method, Acoustics, Ceramics, Lead, Piezoelectric materials, Powders, Radiation effects, Transducers}},
  number       = {{2}},
  pages        = {{225--230}},
  title        = {{{Synthesis of lead-free piezoelectric powders by ultrasonic-assisted hydrothermal method and properties of sintered (K0.48Na0.52)NBO3 ceramics}}},
  doi          = {{10.1109/TUFFC.2014.6722608}},
  volume       = {{61}},
  year         = {{2014}},
}

@article{9743,
  abstract     = {{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.}},
  author       = {{Ageba, Ryo and Kadota, Yoichi and Maeda, Takafumi and Takiguchi, Norihito and Morita, Takeshi and Ishikawa, Mutsuo and Bornmann, Peter and Hemsel, Tobias}},
  issn         = {{1948-5719}},
  journal      = {{Journal of Korean Physical Society}},
  keywords     = {{Hydrothermal method, High-power ultrasonic, PZT thin film, Lead-free piezoelectric materials}},
  number       = {{4}},
  pages        = {{918--923}},
  title        = {{{Ultrasonically-assisted Hydrothermal Method for Ferroelectric Material Synthesis}}},
  doi          = {{10.3938/jkps.57.918}},
  volume       = {{57}},
  year         = {{2010}},
}