Abstract
Piezoelectric properties of a chiral smectic liquid crystalline elastomer are investigated by means of dynamic electromechanical measurements. We have confirmed the piezoelectric constant is fairly large in the chiral smectic C (SmC^*) phase. A relaxation of the piezoelectric constant is observed in the frequency dispersion curve of a director orientated elastomer obtained by a uniaxial deformation. The temperature dependence of the relaxation frequency in the smectic phases is nicely fitted to the Vogel-Fulcher-Tammann law, because the dynamics observed here is closely related to the glass transition phenomena. In addition, a resonance instead of a relaxation is recognized in the case of a biaxial deformed elastomer possessing a macroscopically spontaneous polarization due to the C_2 symmetry. We have explained the emergence of the resonance in the biaxial deformed elastomer on the basis of a contribution of an electric repulsive force between the spontaneous and induced polarizations.
