Dielectric permittivity studies of nematogenic compounds and their binary mixtures showing induced smectic A_d phase

Abstract

The binary mixture of 4-n-pentyl phenyl 4-n′-hexyloxy benzoate (ME6O.5) and p-cyanophenyl trans-4-pentyl cyclohexane carboxylate (CPPCC) shows the presence of induced Smectic A_d phase. In the present work the phase diagram as well as static dielectric permittivity measurements of different mixtures throughout the composition range, are reported. The observed variation of dielectric anisotropy with molar concentration in the nematic and smectic phases is explained, assuming the formation of both homo- and hetero-dimers in the mixture.

Keywords:

• Binary mixture
• Induced smectic phase
• Dielectric permittivity

Acknowledgements

We are grateful to M/s E. Merck, UK, for gifting the liquid-crystal samples used in this work. We are also grateful to Professor R. Paul for useful discussions.