Direct observation of local layer structure defects in a surface stabilized ferroelectric liquid crystal using synchrotron X-ray micro-diffraction

Abstract

Abstract The local layer structure of the zig-zag defect boundaries in thin-surface stabilized ferroelectric liquid crystal cells was studied using a newly developed synchrotron X-ray microbeam. Rocking curves (θ scan) were measured as a function of the sample position. At the broad wall boundary, central peaks appeared (θ=0°) between peaks corresponding to the chevron structure (θ=±δ). At the narrow wall running parallel to the rubbing direction, a central peak also appeared, but only when the sample cell was rotated around the surface normal by about δ (=18°). These observations indicate that the layers at both boundaries are nearly normal to the glass plate. Furthermore, a detailed analysis shows that the layer in the wall sometimes has kinks, indicating edge dislocations at the boundary. X-ray microtopography was used to reveal the fluctuation of the chevron structure over a small region.