Electro-optic and dielectric properties of an antiferroelectric liquid crystal material

Results reported in this paper on the electro-optic properties and dielectr ic relaxation in the SMCA* and SmC* phase of a liquid material as a functio n of sample thickness. The measurements were carried out in 3 mum, 6 mum, a nd 10 mum thick cells. In the whole SmC* phase two modes were obtained in t he low frequency region of the dielectric spectra in each of the three cell s without bias electric field. The relaxation strength of both the modes sh arply decreases with the applied bias dc electric field. One of the modes i s assigned as Goldstone mode, arises due to phase fluctuation and the origi n of the other mode may be related to the space charge accumulated at the i nterface between liquid crystal and the polymer coating. In antiferroelectr ic liquid crystal (SMCA*) phase two switching current peaks were observed o nly in a 3 mum thick cell by applying triangular wave of frequency around 3 0 Hz-40 Hz. Two antiferroelectric modes were obtained in the dielectric spe ctra of SMCA* phase in the low frequency region and the results have been d icussed. Both the results of spontaneous polarization and dielectric studie s reveal that the antiferroelectric behavior in the SMCA* phase is squeezed in each of the three cells.