Resonant X-ray Scattering Studies of Smectic and Columnar Bent-Core Liquid Crystal Phases

Resonant X-ray scattering provides a direct probe of orientational structures in liquid crystals with periodicities that range from molecular dimensions (0.1 nm) to dimensions that can be observed with visible light (1.0 micron). We have recently applied this technique to study the orientational ordering of bent-core molecules in the smectic B$_{2}$ phase and the columnar B$_{1}$ phase. Using resonant scattering ``forbidden'' reflections due to glide or screw symmetry elements can be measured and an analysis of their polarization state enabled us to identify a chiral anticlinic antiferroelecrtic B$_{2}$ phase (Smectic C$_{A}$P$_{A}$) coexisting with an achiral synclinic antiferroelectric B$_{2}$ phase (Smectic C$_{S}$P$_{A}$) [1]. We were also able to determine the structure of a columnar B$_{1}$ phase and study the transition mechanism between the B$_{1}$ and B$_{2}$ phases [2]. \\[4pt] [1] V. Ponsinet, et al., Phys. Rev. E 84, 011706 (2011).\\[0pt] [2] C. Folcia, et al., Phys. Rev. E 84, 010701R (2011).