X-ray studies of the phases and phase transitions of liquid crystals.
A short review is given of recent X-ray diffraction studies of the phases and phase transitions of thermotropic liquid crystals. The areas covered are twist-grain-boundary phases, antiferroelectric phases studied with resonant X-ray diffraction and smectic phases within gel structures. In all areas, X-ray diffraction has played a key role. Nonetheless, open questions remain: the nature of the smectic C variant of the twist-grain-boundary phase, the origin of antiferroelectric phases, and whether novel Bragg glass states exist for smectic A gel samples.
Clegg
Paul S
PS
School of Physics, University of Edinburgh, Mayfield Road, Edinburgh EH9 3JZ, Scotland. pclegg@ph.ed.ac.uk