Dielectric studies of charge stabilized ferroelectric liquid crystal cells

Dielectric investigations have been reported for a thin (2.5 mu m), charge stabilized ferroelectric liquid crystal samples, in the frequency range of 10 Hz to 1 MHz. The charge stabilized ferroelectric liquid crystal cells were prepared by using thick polyamide coated and rubbed substrates for alignment. It has been found by an electro-optical method that the accumulation of free charges at the interface between the ferroelectric liquid crystal (FLC) medium and the alignment layer gives rise to a phenomenon of reverse switching in the cells. The dielectric studies were reported in the smectic C* phase in such cells. The behaviour of dielectric permittivity, particularly the Goldstone mode which comes due to the phase fluctuations of the order parameter has been studied for positive and negative polarity of the bias field in the charge stabilized FLC cells. The unusual behaviour of Goldstone mode for positive and negative polarity bias held has been explained by considering the charge stabilized phenomenon and confirmed by the electro-optical method.