Near neighbour correlations and the dielectric properties of liquid crystals

It is demonstrated experimentally that there can be a reversal of the sign of the dielectric anisotropy (Δε) with decreasing temperature in a nematic. The results are explainable in terms of the Maier-Meier mean field theory and indicate that the occurrence of the smectic phase and the consequent dipole correlations within the smectic layers is not a necessary condition for the sign reversal of Δε