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

摘要

This invention provides a piezoelectric ceramic that can easily regulate resonance frequency-temperature characteristics. A piezoelectric ceramic (2) comprises first and second parts (11 and 12) that are each in a layer form and have been stacked alternately on top of each other. The first and second parts (11 and 12) are formed of, for example, a compound having a bismuth layered structure such as a composite oxide containing at least Sr, Bi and Nb and are different from each other in the degree of orientation of c axis. Since the resonance frequency-temperature characteristics vary depending upon the degree of orientation, the resonance frequency-temperature characteristics as the whole piezoelectric ceramic (2) can easily be regulated by properly combining the first and second parts (11 and 12) having mutually different degrees of orientation.