Piezoelectric porcelain composition

Abstract

Provided is a Sr2-xCaxNaNb5O15 type piezoelectric ceramic composition wherein the inhibition of cracking and an improvement in the piezoelectric characteristics are attained by improving the composition uniformity and the microstructure uniformity. In the basic Sr2-xCaxNaNb5O15 composition, the (Sr, Ca)/Na ratio is changed, whereby the occupancies of Sr, Ca and Na in lattices which constitute the tungsten-bronze type structure and into which Sr, Ca, and Na can enter are reduced to facilitate the entrance of Sr into the lattices and thus inhibit the formation of a secondary phase. Further, a predetermined amount of Al and/or Si is added to lower the sintering temperature and to make the microstructure uniform. Additionally, a predetermined amount of Mn is added to make the polarization easy.

Dependencies are inferred from the claim text.