Dielectric Studies of Monolayer Smectic A Phases of Strongly Polar Liquid Crystals

Abstract

We have investigated the monolayer smectic (A,)-nematic transition in the fourth, sixth and eighth homologs of 4-(4'-alkoxybenzoyloxy)-4'-cyanoazobenzenes. Although the A, -N transition is second order in all the three compounds dielectric studies reveal that the changes in dipolar ordering accompanying the transition are substantially different in the three cases.

Dielectric measurements of liquid crystals

“…The same behaviour has been observed by Nagabhushan et al [18] in the compound 4 OBCAB. The sharp drop in constant ei is due to the effect of dimerisation [19] : in the smectic phase of CBOOA, the antiparallel correlation is stronger than in the nematic phase.…”