- Tytuł:
- Dielectric and X-ray Studies of Eleventh and Twelfth Members of Two Isothiocyanato Mesogenic Compounds
- Autorzy:
-
Jasiurkowska, M.
Budziak, A.
Czub, J.
Urban, S. - Powiązania:
- https://bibliotekanauki.pl/articles/2047170.pdf
- Data publikacji:
- 2006-12
- Wydawca:
- Polska Akademia Nauk. Instytut Fizyki PAN
- Tematy:
-
61.10.Eq
61.66.Hq
64.70.Md
77.22.-d
77.22.Gm - Opis:
- Results of the dielectric and X-ray studies of the long-alkyl-chain members (n=11, 12) of two homologous series: nBT (4-n-alkyl-4'-isothiocyanato-biphenyl) and nCHBT (4-trans-4'-n-alkyl-cyclohexyl-isothiocyanato-benzene) in their liquid crystalline phases are presented. These compounds exhibit different polymorphisms: the nematic phase for $n$CHBTs and the smectic E and smectic A phases for nBTs. The dielectric measurements were performed in a wide frequency range of 1 kHz-3 GHz. The layer thickness in the smectic E and smectic A phases and the orthorhombic unit cell parameters of the smectic E phase were determined using the small angle X-ray diffraction method. In the smectic E phase the layer-thickness-to-molecular-length ratios are found to be close to 1. The corresponding ratios observed for the smectic A phase of $n$BTs are considerably higher (≈1.24), which indicates that an alternating head-to-tail arrangement of molecules in the layers is favored. The rotational dynamics of molecules in the smectic E phases is discussed in relation to their packing in a unit cell.
- Źródło:
-
Acta Physica Polonica A; 2006, 110, 6; 795-805
0587-4246
1898-794X - Pojawia się w:
- Acta Physica Polonica A
- Dostawca treści:
- Biblioteka Nauki
Artykuł