DOI: 10.1051/jp2:1994106
J. Phys. II France 4 (1994) 407-412
Columnar and smectic ordering in a TGB
phase
A. C. Ribeiro1, 2, A. Dreyer1, L. Oswald1, J. F. Nicoud1, A. Soldera1, D. Guillon1 and Y. Galerne1
1 Institut de Physique et Chimie des Matériaux de Strasbourg, Groupe des Matériaux Organiques, ICS, 6 rue Boussingault, 67083 Strasbourg Cedex, France
2 Centro de Física da Matéria Condensada, Av. Gamma Pinto, 1699 Lisboa Codex, Portugal
(Received 14 October 1993, revised 21 January 1994, accepted 27 January 1994)
Abstract
Optical textures characteristic of cholesteric and columnar structures were simultaneously detected for the first time in
the same mesophase of a liquid crystal. However, X-ray diffraction measurements show that the mesophase under consideration
is smectic A in nature. We show here that the compound presents, indeed, a twist grain boundary (TGB) phase within a large
temperature range, and we propose an explanation of the supramolecular organization in this phase.
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