Method of polarization-treating piezoelectric body

摘要

A DC voltage is applied to a piezoelectric body for polarization treatment in the air and in an atmosphere with a temperature equal to or higher than an aging temperature, and then, the piezoelectric body is aged at the aging temperature. The polarization degree is determined based on the frequency characteristic while the piezoelectric body is polarized. The application of the DC voltage is stopped at the time when the measured polarization degree reaches a set level. The set level is determined based on a correlation between the polarization degree obtained immediately before the application of the DC voltage is stopped and the stable polarization degree obtained after the aging and the ordinary temperature restoration following the stop of the voltage application.