Resonant scattering from liquid crystal devices: an in-situ structural probe for the smectic phases 

Resonant X-ray scattering is a relatively new technique in the field of liquid crystals and in recent years has been used to investigate the structures of the SmC* sub-phases. This work has been carried out on several materials which include either a sulfur or selenium atom and has revealed the detailed biaxial structure of the four layer intermediate (ferrielectric) phase. Resonant X-ray scattering has also been used to produce the first in-situ measurements of the chiral smectic sub-phases in a liquid crystal device. Both the antiferroelectric and the four-layer intermediate phases have been observed via this technique in a device geometry. Electric field studies have also been carried out in these phases whilst monitoring phase structure simultaneously. In this paper I will summarize the most up-to-date results from resonant scattering in free-standing films and discuss resonant scattering experiments on liquid crystal devices.