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

Abstract

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 ferroelectric SmC Ã 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.

Orientational and structural properties of ferroelectric liquid crystal with a broad temperature range in the SmC*phase by13C NMR, x-ray scattering and dielectric spectroscopy

“…However, a decrease in d values on cooling is due to (i) the increasing order of the long molecular axes inside the plane of the smectic layers and (ii) a slight increase of the tilt angle of molecules. For the studied material the average lateral intermolecular distance has been determined: 4.9 Å in the N * phase (at T = 90 • C) and 4.6 Å in the SmC * phase (at T = 76 • C) [28] indicating the increase of the close packing of molecules on cooling.…”