Characteristic P-E and S-E relationships of hard PZT ceramics under high drive conditions

The use of hard PZT ceramic as the piezoelectric element in high power acoustic sources is well established. With the onset of high electric drive levels (>0.6 kV/mm), such materials exhibit increasing dielectric non-linearity and loss as a result of hysteretic ferroelectric domain wall motion. The aims of the present work are to derive the effective high field dielectric and piezoelectric coefficients of hard PZT ceramics by analysis of the measured P-E (polarisation-field) and S-E (strain-field) relationships respectively. The paper deals with the effects of field amplitude and cycling time on the behaviour of standard commercial materials.