Chirality, surface anchoring, and the cholesteric-smectic A phase transition

Abstract

Magnetic Freedericksz transition measurements were performed on samples of chiral and racemic mixtures in the cholesteric/nematic phase. We found that the quantity Ф, which is defined as the threshold field H _th times the cell thickness, is larger for the chiral than for the racemic mixtures. This result is inconsistent with chiral contributions to the anchoring strength potential. Instead, the data support a model by Lubensky wherein the transition temperature to the smectic A phase is suppressed in a chiral liquid crystal.