Dielectric permittivity of antiferroelectric liquid crystals

Abstract

Abstract The complex dielectric permittivity has been measured as a function of the frequency, the temperature and the biasing field for the antiferroelectric liquid crystal tolan C8 and C10. At the transition from the ferrielectric phase to the antiferroelectric one the remarkable maximum has been observed for low frequencies on the curves ε(T). This contribution to ε is discussed as an antiphase azimuthal mode in the frame of the model assuming that in the SmCγ* phase the tilt angle is practically constant, and the difference in the azimuthal angle in the adjacent layers is different from 180°.