| Abstract: | The knowledge of the material parameters related to the microscopic structure of liquid crystals is one of the main problems in the construction of the liquid crystal devices. In the case of ferroelectric liquid crystals, the viscoelastic properties are very important as they determine the switching speed and the threshold voltage in displays. There exist several experimental methods for measurements of viscosity and elasticity constants in tilted smectic phases which exploit various phenomena for deformation detection, e.g., light transmission, polarization current, light modulation, dielectric constant, and helix deformation or helix unwinding. In this article, we compared the results of measurements obtained for the same material using various methods. The experiments proved that the correct bulk values of the mentioned material constants can be determined using thick, homeotropically aligned samples only. |
