PIEZOELECTRIC AND PYROELECTRIC PROPERTIES IN FERROELECTRIC KTA0.3NB0.7O3 CERAMICS

Piezoelectric and pyroelectric properties of KTa0.3Nb0.7O3 ceramics wh ich belong to the perovskite-ferroelectric ABO(3) family, were studied . The piezoelectric constants (d(31) = 18 pC/N, d(33) = 28 pC/N and d( 15) = 19 pC/N) of these ceramics are higher than that for KNbO3. We fo und that the amplitudes of the fundamental frequency and its overtones for the thickness vibrations depend on the temperature in the ferroel ectric phase. The value at room temperature of the pyroelectric coeffi cient (p = 10 nC cm(-2) K-1) and the spontaneous polarization (P-s = 3 5 mu C cm(-2)) are in agreement with that of KNbO3.