Determination of the order parameter of 4-(trans-4 '-n-hepty-cyclohexyl)-isothiocyanato-benzene by means of dielectric relaxation spectroscopy

Studies of the dielectric relaxation were made for the isotropic and nemati c phases of 4-trans-4 ' -n-(heptylcyclohexyl)isothiocyanatobenzene, (C7H15- CyHx-Ph-N=C=S) (7CHBT) in the frequency range from 100 kHz to 1 GHz. In the nematic phase two relaxation processes were recorded for the dielectric pe rmittivity component measured parallel to the molecular orientation (direct or (n) over right arrow) and three relaxation processes for the perpendicul ar permittivity component. The elementary contributions to the total dielec tric absorption are found to be of the Debye-type. The strength of the nema tic potential and the nematic order parameter as a function of temperature were estimated. The results obtained were compared with the predictions of the Maier-Saupe theory.