Piezoelectric relaxation in bismuth titanate based ferroelectric ceramics
The dynamic piezoelectric behavior of bismuth titanate based ferroelectric ceramics has been characterized as a function of the frequency and temperature. Both increase and decrease of the piezoelectric coefficient with the frequency have been observed. The influence of the microstructure and the anisotropy of properties on relaxation are discussed. A model based on the properties of a composite of two materials connected in series is proposed to explain the relaxation.