An ANNNXY model for transversely polarised non-chiral smectic liquid crystals
Raman Research Institute - C.V. Raman Avenue, Bangalore 560080, India
Accepted: 22 June 1997
We propose an axial next nearest neighbour xy (ANNNXY) model to describe phase transitions in smectic liquid crystals made of bent non-chiral molecules which exhibit transverse polarisation. The model includes a polar and a quadrupolar NN coupling as well as a competing antiferroelectric NNN coupling between the layers. As the temperature is lowered, the most general sequence of phases predicted by the model is: paraelectric-helielectric (H)-antiferroelectric-reentrant H-4 layer antiphase-helielectric (Hf)-ferroelectric. We believe that Hf and the antiphase have been seen in very recent experiments.
PACS: 77.80.-e – Ferroelectricity and antiferroelectricity / 77.80.Bh – Phase transitions and Curie point / 77.84.Nh – Liquids, emulsions and suspensions; liquid crystals
© EDP Sciences, 1997