Induced Piezoelectricity in Aurivillius Relaxor Ceramics with Composition Pb x Bi 4 Ti 3+x O 12+3x , x = 2 and 3

Abstract

Results of the induced piezoelectric effect in Aurivillius relaxor ceramics with composition Pb x Bi 4 Ti 3+x O 12+3x , x = 2 and 3, (P2BIT and P3BIT) are shown. The materials P2BIT and P3BIT have been reported previously as relaxor ferroelectrics having a maximum of the dielectric constant at temperatures of 285 and 235°C, at a frequency of 1 MHz, respectively. By the application of a bias field on non-poled samples it is possible to induce the piezoelectric effect. The piezoelectric constants were measured by using the resonant-antiresonant method. The compound P2BIT, for a bias field of 7.4 kV/cm, showed coupling factors k p and k T ∼0.16 at temperatures of 200°C; the piezoelectric coefficient d 31 was higher than m 60 pC/N at this temperature, and possesses a rather constant value in a 50°C range. The compound P3BIT, showed k p ∼0.12 between room temperature and 100°C; and the piezoelectric coefficient d 31 exceeds m 40 pC/N at 100°C. This results represent a new step in the search of high temperature piezoelectric ceramics.