Determination of the order parameter of 4-(trans-4,-n-heptyl-cyclohexyl)-isothiocyanato-benzene by means of dielectric relaxation spectroscopy
[ 1 ] Katedra Spektroskopii Optycznej (KS), Wydział Fizyki Technicznej, Politechnika Poznańska | [ P ] employee
2001
scientific article
english
EN Studies of the dielectric relaxation were made for the isotropic and nematic phases of 4-(trans-4'-n-heptylcyclohexyl)isothiocyanatobenzene, (C/sub 7/H/sub 15/-C/sub y/H/sub x/-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 permittivity component measured parallel to the molecular orientation (director n/spl I.oarr/) and three relaxation processes for the perpendicular permittivity component. The elementary contributions to the total dielectric absorption are found to be of the Debye-type. The strength of the nematic 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.
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