Finnegan, Henderson, Farabow, Garrett & Dunner, L.L.P.
Piezoelectric sintered ceramics and piezoelectric ceramic elements constituted thereby
 A piezoelectric sintered ceramic made of (a) 100 parts by weight of main components having a composition represented by the general formula: (Pb.sub.1-y M.sub.y)(Zr.sub.z Ti.sub.1-z)O.sub.3, wherein M is at least one element selected from the group consisting of Sr, Ba and Ca, and y and z are numbers satisfying 0.01.ltoreq.y.ltoreq.0.10, and 0.51.ltoreq.z.ltoreq.0.56, respectively; (b) 0.05-1.0 parts by weight, as Fe.sub.2 O.sub.3, of Fe; and (c) 10-1000 ppm of Ag. 
Hitachi Metals, Ltd.
H H
H01L H01L
inventional inventional
Shigeru Junichi Hiromi Hideko
Jomura Watanabe Kikuchi Fukushima