Study of ferroelectric liquid crystals with 2-alkoxypropionate chiral group by X-ray measurements

We present the X-ray study of three series of ferroelectric liquid crystalline materials with a 2-alkoxypropionate chiral group in order to establish the connection of physical properties and the number of carbon atoms in the non-chiral chain. All materials have the ferroelectfic SmC* phase in a broad temperature range. Using X-ray diffraction of non-oriented samples we have identified low temperature non-tilted SmX phase as the SmB phase. The thickness of smectic layers and value of the average distance between the long axes of neighbouring molecules were determined. The temperature dependence of the layer spacing was studied in all phases.