PIEZOELECTRIC CERAMIC, PROCESS FOR PRODUCING SAID PIEZOELECTRIC CERAMIC, PIEZOELECTRIC RESONATOR, AND PROCESS FOR PRODUCING PIEZOELECTRIC RESONATOR

摘要

A piezoelectric ceramic whose resonance frequency temperature characteristic can be easily adjusted is provided. A piezoelectric ceramic (2) is comprises first and second parts (11 and 12) which are layers and are alternately stacked. The first and second parts (11 and 12) are each composed of a compound having a bismuth layer structure, such as a complex oxide containing at least Sr, Bi, and Nb, and have degrees of c-axis orientation different from each other. Since the resonance frequency temperature characteristics change according to the degree of orientation, the first and second parts (11 and 12) having different degrees of orientation are adequately combined so that the resonance frequency temperature characteristics of the piezoelectric ceramic (2) as a whole can be easily adjusted.