Large Piezoelectric Effect Induced by Direct Current Bias in PMN:PT Relaxor Ferroelectric Ceramics

Abstract

The longitudinal piezoelectric effect induced by a direct current bias field was investigated in PMN:PT family of relaxor ferroelectric ceramics in the frequency range from 0. 1 Hz to 50 kHz. The piezoelectric d 33 coefficient was studied by measuring the strain induced by the applied electric field. Under the 10 kHz driving field, the large piezoelectric strain coefficient, d 33 , of 800 pC/N is obtained. The piezoelectric strain coefficient related dielectric and electrostrictive parameters were also studied under direct current bias and the d 33 coefficient was calculated by the equation d 33 =2 Q 11 P 3 ε 33 . The results are in good agreement with the directly measured ones. The dispersion of the piezoelectric effect is mainly due to the dielectric dispersion.