Showing papers by "Grzegorz Czechowski published in 1994"
TL;DR: In this paper, the results of a dielectric relaxation study of liquid crystalline title com pound (C3H7-Cyhx-Ph-NCS, 3-CHBT) in the isotropic and the nematic phase (measurements with electric field parallel to alignment) are presented.
Abstract: Abstract The results o f a dielectric relaxation study (in the frequency region from about 1 kHz to 1 GHz) of the liquid crystalline title com pound (C3H7-Cyhx-Ph-NCS , 3-CHBT) in the isotropic and the nematic phase (measurements with electric field parallel to alignment) are presented. The spectra of both phases can be described by two relaxation processes of Debye-type, possibly related to rotation around the long and short molecular axes.
6 citations
TL;DR: In this paper, a homologous series of 4-isothiocyanatophenyl 4-(trans-4-alkylcyclohexyl)benzoates was synthesized and their phase transition temperatures and enthalpies, smectic layer spacing and dielectric permittivity were measured.
Abstract: The homologous series of 4-isothiocyanatophenyl 4-(trans-4-alkylcyclohexyl)benzoates (with n-alkyl chain from ethyl to dodecyl) were synthesized and their phase transition temperatures and enthalpies, smectic layer spacing and dielectric permittivity were measured. It was observed that the smectic A, layer spacing is expanding from d/l ∼ 1 to d/l ∼ 1.1 when the alkyl chain increases from butyl to dodecyl. It was proposed to term the smectic A1 with d/l > 1 as the enhanced smectic A1 (Ale).
6 citations
TL;DR: In this paper, the results of dielectric relaxation measurements (1 kHz ÷ 1 GHz) for series of mesogenic molecules CnH2n+1φ-φφ -CH2CH2-NCS, n-TPEB, (n = 7 ÷ 10) in the isotropic phase were presented.
5 citations
TL;DR: In this paper, the temperature's behavior of the splay and band elastic constants for n-octyloxycyanobiphenyl (8-OCB) has been studied.
Abstract: The temperature's behaviour of the splay and band elastic constants for n-octyloxycyanobiphenyl (8-OCB) has been studied. The constants have been determined on the basis of threshold values BO and Uo resulting from the Frederiks transitions in magnetic and electric field, respectively. The K11 and K33 show the pretransitional nematic-smectic A effect.