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Induced piezoelectricity in aurivillius relaxor ceramics with composition Pb<inf>x</inf>Bi<inf>4</inf>Ti<inf>3+x</inf>O<inf>12+3x</inf>, 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 235C, 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 200C; the piezoelectric coefficient d 31 was higher than - 60 pC/N at this temperature, and possesses a rather constant value in a 50C range. The compound P3BIT, showed k p ~0.12 between room temperature and 100C; and the piezoelectric coefficient d 31 exceeds - 40 pC/N at 100C. This results represent a new step in the search of high temperature piezoelectric ceramics. © 2002 Taylor & Francis.