Effect of Smectic Ordering on the Dielectric Properties of Reentrant Nematic Mixtures

Abstract

We have measured the static dielectric constants ε_∥ and ε_⊥ as well as the low-frequency dispersion of ε_par for mixtures of two eutectic compositions exhibiting a reentrant nematic phase over a range of concentration. The dielectric properties of a nematic mixture, whose concentration is close to the critical concentration ( C _cr) at which the smectic phase appears, are found to be markedly different from those for a concentration far away from ( C _cr). This can be understood as being due to an increase in the smectic like ordering in the nematic phase as the critical concentration is approached.