Thermotropic, refracting and thermo-optical properties in three homologs of 4-n-alkyl-4’-cyanobiphenyls

  • A. Nesrullajev
Keywords: liquid crystals, refractive properties, optical birefringence, phase transitions


Investigations of temperature behaviour of the mean refractive index n, ordinary no and extraordinary ne refractive indices, and birefringence Δn have been carried out for three homologues of 4-n-alkyl-4’-cyanobiphenyls (n = 8, 10, 12). The principal polarizabilities α0 and αe, effective geometry parameter αeg and average polarizability αave have been calculated using the isotropic internal field model (Vuks approach). Temperature behaviour of the order parameter in regions of the smectic A–nematic, nematic–isotropic liquid and smectic A–isotropic liquid is discussed. All of the optical and orientational parameters, which have been obtained in this work, are in good agreement with the theoretical approach.
Condensed Matter Physics and Technology