Electro-optic effect and influence of bias electric field on the goldstone mode dielectric behavior in smectic C* phase and cell thickness dependence of the dielectric permittivity of a ferroelectric liquid crystal mixture

Results reported here on the spontaneous polarization, switching time, rotational viscosity and Goldstone mode dielectric strength and relaxation frequency as a function of electric field in the SmC* phase of a Ferroelectric liquid crystal mixture. It has been observed that the spontaneous polarization and the rotational viscosity are almost, independent of the amplitude of the applied field, The response time however depends on the applied field. The field required to unwound the helix is much larger than the structurally similar compounds. The dielectric strength of the Goldstone mode is found to decrease with the increase of bias electric field bur the relaxation frequency of the Goldstone mode on the other hand increases with the increase of bias electric field. Results also show that the critical field E-C, for unwinding the helical structure in SSMC* phase depends on the temperature. Rotational Viscosity of the Goldstone mode has also been determined under D.C bias field in the SmC* phase. Dielectric permittivity is found to increase with the increase of cell thickness. The increase of dielectric permittivity and the temperature of transition (T*(C)), in a thicker cell have also been explained considering theoretical relations developed earlier.