Piezoelectricity in NaNbO₃ceramics

Piezoelectric and dielectric measurements were performed on different batches of polarized NaNbO 3 ceramics. It has been established that, as a result of polarization, in these ceramics there appears a metastable ferroelectric phase existing for a long time. The presence of this phase manifests itself as a piezoelectric effect accompanied by a piezoresonance dispersion of the dielectric permittivity. The magnitudes and temperature dependencies of the piezoelectric coefficients d 33 of the NaNbO 3 ceramics were measured for the first time.