Investigation of the dielectric constants and the diamagnetic anisotropies of cyanobiphenyls (CB), cyanophenylcyclohexanes (PCH), and cyanocyclohexylcyclohexanes (CCH) in the nematic phase

Abstract

We have measured the dielectric constants of cyanobiphenyls (CB), cyanophenylcyclohexanes (PCH), and cyanocyclohexylcyclohexanes (CCH) using a capacitance bridge with a dielectric cell having a guard ring. The ratio Δχ/Δε was also measured for these materials using a new technique which is applicable when Δχ is small or even negative. As a surprising result we have found that this ratio is almost independent of temperature. The temperature dependence of the diamagnetic anisotropies and the dielectric constants of these compounds are given and the results are discussed in terms of the molecular properties.