Eur. Phys. J. E (2008) 27: 397-405
https://doi.org/10.1140/epje/i2008-10409-1

Regular Article

Experimental study of de Vries properties in antiferroelectric smectic liquid crystals

¹ Department of Electronic & Electrical Engineering, Trinity College, University of Dublin, Dublin 2, Ireland
² School of Electrical & Communication Engineering, Dublin Institute of Technology, Dublin 8, Ireland
³ Institute of Chemistry, Military University of Technology, Warsaw, Poland

^* e-mail: jvij@tcd.ie

Received: 22 June 2008
Revised: 9 October 2008
Accepted: 11 November 2008
Published online: 23 December 2008

Abstract

Results of the experimental study on different antiferroelectric liquid crystal (AFLC) materials are presented using a number of techniques such as the optical birefringence, electro-optics and the measurements of optical thickness of free-standing films. Despite differences in the molecular structures of the various AFLC materials studied, these are found to exhibit a de Vries type of smecticA^* (SmA ^*) properties in a temperature range higher than SmC ^* . This correlation leads to the conclusion that these two classes of liquid crystals are related to each other. Furthermore, we suggest that these arise from the same physical mechanism, namely the existence of the weak synclinic (or reduced anticlinic) correlations between the neighbouring molecular tilt directions.