@ARTICLE{Maeda2011,
  author = {Takafumi Maeda and Tobias Hemsel and Takeshi Morita},
  title = {Improved Process for Hydrothermal Lead-Free Piezoelectric Powders
	and Performances of Sintered (K0.48Na0.52)NbO3 Ceramics},
  journal = {Japanese Journal of Applied Physics},
  year = {2011},
  volume = {50},
  pages = {07HC01},
  abstract = {In this study, we report some improvements in a hydrothermal method
	for lead-free piezoelectric powders and the performance of the sintered
	(K$_{0.48}$Na$_{0.52}$)NbO$_{3}$ ceramics. To increase the obtained
	powder weight per source solution volume, the hydrothermal reaction
	conditions were modified. This improvement is important for mass
	production; however, it resulted in a larger particle size dispersion.
	Therefore, we examined to introduced the ball milling process that
	is useful for dense (K$_{0.48}$Na$_{0.52}$)NbO$_{3}$ ceramics. When
	a large amount of powder was obtained, it took a long time to eliminate
	the residual alkaline ions in the hydrothermal powders by a washing
	process. Therefore, a neutralization was conducted in the powder
	washing process. Using this powder, a solid solution of (K,Na)NbO$_{3}$ceramics
	was synthesized. The relative density was successfully increased.
	Concerning the electrical properties, the relative permittivity was
	improved, and the piezoelectric constant d$_{33}$ was also increased
	from 114 to 130 pC/N.},
  bdsk-url-1 = {http://www.ems.k.u-tokyo.ac.jp/morita/Papers/56_maeda_JJAP.pdf},
  file = {Maeda2011.pdf:Maeda2011.pdf:PDF},
  numpages = {4},
  publisher = {The Japan Society of Applied Physics},
  timestamp = {2013.09.26},
  url = {http://www.ems.k.u-tokyo.ac.jp/morita/Papers/56_maeda_JJAP.pdf}
}