Rupnik, P.M., Hanžel, E., Lovšin, M. et al. (5 more authors) (2025) Antiferroelectric Order in Nematic Liquids: Flexoelectricity Versus Electrostatics. Advanced Science, 12 (9). 2414818. ISSN 2198-3844
Abstract
The recent discovery of ferroelectric nematic liquid crystalline phases marks a major breakthrough in soft matter research. An intermediate phase, often observed between the nonpolar and the ferroelectric nematic phase, shows a distinct antiferroelectric response to electric fields. However, its structure and formation mechanisms remain debated, with flexoelectric and electrostatics effects proposed as competing mechanisms. By controlling the magnitude of electrostatic forces through ion addition in two representative ferroelectric nematic materials, it is shown that the primary mechanism for the emergence of antiferroelectric order is the flexoelectric coupling between electric polarization and splay deformation of the nematic director. The addition of ions significantly expands the temperature range over which the antiferroelectric phase is observed, with this range increasing with increasing ion concentration. Polarizing optical microscopy studies and second harmonic generation (SHG) microscopy reveal the splayed structure modulated in 2D, while SHG interferometry confirms its antiferroelectric character. The model previously used to describe pretransitional behavior is extended by incorporating the electrostatic contribution of ions. The model shows qualitative agreement with the experiments, accurately reproducing the phase diagram and temperature-dependent evolution of the modulation period of the observed structure.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2025 The Author(s). This is an open access article under the terms of the Creative Commons Attribution License (CC-BY 4.0), which permits unrestricted use, distribution and reproduction in any medium, provided the original work is properly cited. |
Keywords: | antiferroelectric nematic; electrostatics; ferroelectric nematic; flexoelectricity; polarity in liquids |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Chemistry (Leeds) The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Physics and Astronomy (Leeds) > Soft Matter Physics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 14 Jan 2025 11:35 |
Last Modified: | 24 Mar 2025 16:01 |
Status: | Published |
Publisher: | Wiley |
Identification Number: | 10.1002/advs.202414818 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:221692 |