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

Author

Bauman, D. ; Jadzyn, J. ; Czechowski, G.

Author_Institution

Fac. of Tech. Phys., Poznan Univ. of Technol., Poland

Volume

8

Issue

3

fYear

2001

fDate

6/1/2001 12:00:00 AM

Firstpage

381

Lastpage

384

Abstract

Studies of the dielectric relaxation were made for the isotropic and nematic phases of 4-(trans-4´-n-heptylcyclohexyl)isothiocyanatobenzene, (C₇H ₁₅-C_yH_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&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

Keywords

dielectric relaxation; molecular orientation; nematic liquid crystals; organic compounds; permittivity; 100 kHz to 1 GHz; 4-(trans-4´-n-heptyl-cyclohexyl)isothiocyanato-benzene; Maier-Saupe theory; dielectric absorption; dielectric relaxation spectra; isotropic phase; nematic order parameter; nematic phase; nematic potential; order parameter; permittivity; Dielectric measurements; Electrochemical impedance spectroscopy; Frequency; Liquid crystal displays; Liquid crystals; Magnetic field measurement; Permittivity; Phase measurement; Physics; Temperature;

fLanguage

English

Journal_Title

Dielectrics and Electrical Insulation, IEEE Transactions on

Publisher

ieee

ISSN

1070-9878

Type

jour

DOI

10.1109/94.933348

Filename

933348