Characterization of focal conics in chiral smectic C liquid crystals by X‐ray microdiffraction

Abstract

Focal conics consisting of an ellipse and a hyperbola in chiral smectic C liquid crystals aligned in surface‐stabilized cells of medium thickness (about 25 µm cell gap) were characterized in relation to the chevron structure by synchrotron X‐ray microdiffraction. The focal conic texture is embedded in the chevron structure with a relatively sharp interface. The deformed layer of the focal conics is a kinked bookshelf consisting of a few slightly bent segments for small focal conics, whereas it is a bookshelf layer for large focal conics. Around the focus of the ellipse toward the hyperbola, a complicated layer structure appears, although the core region of small layer curvature has been hardly observed within the present experimental sensitivity. The broad and narrow walls of a zigzag defect in the same cell are analyzed for comparison.

Acknowledgements

The authors would like to thank Prof. H. Takezoe and Mr. T. Noma for their valuable discussion on this work. They would also like to thank the staff of PF for their help during experiments.