The study of phase transitions of new ferroelectric liquid crystals with chiral 2-alkoxipropionate groups

Abstract

We present the study of the phase transitions of liquid crystalline substances from the series of new synthesized chiral liquid crystals with 2-alkoxipropionate chiral groups. The substances studied possess, in a broad temperature range, ferroelectric SmC*phase. with high spontaneous polarization [1]. High spontaneous polarization (Ps) together with low viscosity are important properties, which can ensure high switching velocity. Dielectric measurmemts have shown that during cooling from SmC*phase there forms an unidentified SmN phase which is neither polar, nor antiferroelectric. Structural studies have shown that this phase can be identified as an SmB phase; which is in accordance with dielectric measurements, as indicated also by the calculated values of the molecular parameters, as well as their temperature dependence. Dielectric and structural studies served as the basis for establishing the phase diagrams of the studied liquid crystalline substances.