Smectic C* Chevron Layer Structure Studied by X-Ray Diffraction

Layer structures in chiral smectic C ( S C * ) phases were studied by high-resolution X-ray diffraction. The existence of a chevron layer structure was confirmed even in thick cells such as 350 µm and even in a compound with the phase sequence of N * - S C * . Cells made by a SiO oblique-evaporation technique gave two diffraction patterns; a single peak was observed when the evaporation directions of top and bottom glasses were set in opposite directions (antiparallel), while two peaks were observed in the case of the glasses set in the same direction (parallel). Thus, the chevron structure was confirmed to exist quite generally except for in the SiO antiparallel cells.