Identification of New Assembly Mode in the Heliconical Nematic Phase via Tender Resonant X-ray Scattering

TL;DR

This study uses tender resonant X-ray scattering to reveal a new self-assembly mode in the heliconical nematic phase, enhancing understanding of molecular packing and resonance effects in complex liquid crystal structures.

Contribution

First quantitative demonstration of energy dependence of scattering peaks in the NTB phase, identifying a novel self-assembly mode in liquid crystal dimers.

Findings

Energy dependence of scattering peak follows complex refractive indices.

Identified a new self-assembly mode in the NTB phase.

Demonstrated resonance effects in heliconical nematic structures.

Abstract

Helical structures are exciting and are utilized in numerous applications ranging from biotechnology to displays to medicine. Accurate description and understanding of resonance effects in helical structures provides crucial knowledge on molecular packing beyond positional ordering. We exam-ined the manifestation of resonance effects in a nematic phase with heliconical structure, the so called twist bend nematic (NTB) via tender resonant X-ray scattering (TReXS) at the sulfur K-edge. We demonstrate for the first time quantitatively that the energy dependence of the scattering peak in the NTB phase follows the energy dependence of the complex refractive indices measured by X-ray absorption. This allows us to identify a new self-assembly mode for specific sets of liquid crystal dimers in the NTB phase. We anticipate that new avenues in the exploration of complex orientational structures both in static as well as in dynamic modes induced by external stimuli will be pursued.