Molecular organization in the twist-bend nematic phase by resonant X-ray scattering at the Se K-edge and by SAXS, WAXS and GIXRD

摘要

Using a novel Se-labelled dimer mixed with DTC5C7 aligned by magnetic field,the twist-bend nematic phase (Ntb) in dimers was studied by hard X-ray resonantscattering and by small and wide angle X-ray scattering (SAXS, WAXS). Resonantdiffraction spots indicated a helix with a 9-12 nm pitch in the Ntb phase.Unprecedentedly high helix orien-tation enabled deconvolution of global andlocal order parameters. This, combined with simultaneous resonant andnon-resonant SAXS and WAXS data, allowed us to construct a modified model ofthe Ntb phase matching twisted molecular conformations and the localheliconical director field.