Piezoelectricity in NaNbO3 ceramics

Piezoelectric and dielectric measurements were performed on different batch es of polarized NaNbO3 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 itsel f as a piezoelectric effect accompanied by a piezoresonance dispersion of t he dielectric permittivity. The magnitudes and temperature dependencies of the piezoelectric coefficients d(33) of the NaNbO3 ceramics were measured f or the first time.