Ultra-short helix pitch and spiral ordering in cholesteric liquid crystal revealed by resonant soft X-ray scattering

0556090 - FZÚ 2023 RIV GB eng J - Journal Article
Smekhova, A. - Novotná, Vladimíra - Fekete, Ladislav - Abrudan, R. - Fondell, M. - Hamplová, Věra - Ostrovskii, B.I.
Ultra-short helix pitch and spiral ordering in cholesteric liquid crystal revealed by resonant soft X-ray scattering.
Soft Matter. Roč. 18, č. 1 (2022), s. 89-96. ISSN 1744-683X. E-ISSN 1744-6848
R&D Projects: GA MŠMT LTC19051
Institutional support: RVO:68378271
Keywords : cholesterics * resonant X-ray * AFM
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 3.4, year: 2022
Method of publishing: Open access

The spontaneous formation of chiral structures offers a variety of liquid crystals phases that could be further tailored for practical applications. In our work, the characteristic features of spiral ordering in the cholesteric phase of compound EZL10/10 were evaluated. To disclose resonant reflections related to a nanoscale helix pitch, resonant soft X-ray scattering at the carbon K edge was employed. The angular positions of the observed scattering peaks reveal a half-pitch of the spiral ordering 52 nm indicating the full pitch of about 104 nm at room temperature. No scattering peaks were detectable in the isotropic phase at higher temperatures. The broadening of the peaks points to a presence of coherently scattering domains formed by cholesteric spirals with lengths of about five pitches. The characteristic lengths extracted from the resonant soft X-ray scattering experiment agree well with the periodicity observed in the cholesteric phase by means of atomic force microscopy.
Permanent Link: http://hdl.handle.net/11104/0330468