The Study of the Guest Host Effect in Thin Aligned Liquid Crystal Film by Raman Spectroscopy

Abstract

In the paper the nematic liquid crystal 5CB (4-pentyl-4′-cyanobiphenyl) with an embedded azo dye in the aligned thin films has been investigated by Raman scattering spectroscopy. The purpose of this paper is the determination of the dye influence on the orientational order of the host molecules in the mesophase as well as on the nematic isotropic transition temperature of 5CB. The study was performed for the different dye concentrations and the different thicknesses of the samples. The second (P₂ and fourth (P₄) order parameters have been determined experimentally and the graphs of the molecular distribution functions of the liquid crystal molecules in the oriented films are presented.