PIEZOELECTRIC PORCELAIN COMPOSITION

摘要

PROBLEM TO BE SOLVED: To obtain a piezoelectric porcelain composition having an electro- mechanical coupling coefficient kt (>=10%) which is applicable value for practical use as a piezoelectric ceramic device by improving a electro-mechanical coupling coefficient of the piezoelectric porcelain composition composed of a bismuth layered compd. as a main component. SOLUTION: A main component of the objective composition is expressed by the formula (Sr1-x Mx )Bi2 Nb2 O9 (wherein M is a bivalent metal element) and further (x) is in a range of 0<=x<=0.3, and Mn is contained by <=1.0 wt.% (>0) expressed in terms of MnCO3 . A remarkable effect is obtained in case that M in the formula is composed of at least one of Ca and Ba.