Dielectric Properties of Nematic and Ferroelectric Liquid Crystals

Different contributions to the dielectric permittivity in two different ferroelectric liquid crystal materials are studied, with emphasis on the Soft mode and the Golstone mode. Also in three nematic liquid crystals, the dielectric permittivity was studied as a function of temperature and frequency. Experimentally, the complex dielectric permittivity was studied as a function of temperature in the frequency range 5 Hz-13 MHz. The Soft mode dielectric behavior was studied as a function of frequency and bias electric field. In the smectic C*, I*, and J* phases, the frequency dependence of the dielectric contribution of the Golstone mode was measured.