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Observation of Ferroelectricity in a Thermotropic Nematic Liquid Crystal Using its Spectacular Electro-Optics

ORAL

Abstract

We have synthesized and studied the literature compound RM734 [1], a polar rod shaped molecule exhibiting a typical nematic phase and a second nematic phase assigned to be a "splay nematic" state [2]. We find that the second phase is rather a thermotropic ferroelectric nematic, an identification based on the first observation in a nematic of the defining characteristics of ferroelectricity: (1) the formation, in absence of applied electric field, of spontaneously polar domains of opposite sign of polarization separated by distinct domain boundaries; and (2) field-induced polarization reversal mediated by movement of these domain boundaries. A truly remarkable feature of this phase is the magnitude of its spontaneous polarization, saturating at 6 μC/cm2, the largest ever reported for an organic material or for any fluid, and larger than that of all but a few crystalline ferroelectrics.

Works Cited

[1] Mandle RJ,et al. (2017). Rational Design of Rod-Like Liquid Crystals Exhibiting Two Nematic Phases. Chemistry - A European Journal, 23 14554-14562.
[2] Mertelj, A. et al. (2018). Splay Nematic Phase. Phys. Rev. X, 8, 041025.

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Presenters

  • Xi Chen

    Department of Physics, University of Colorado, Boulder

Authors

  • Xi Chen

    Department of Physics, University of Colorado, Boulder

  • Eva Korblova

    Department of Chemistry, University of Colorado, Boulder

  • Renfan Shao

    Department of Physics, University of Colorado, Boulder

  • Leo Radzihovsky

    University of Colorado, Boulder, Department of Physics, University of Colorado, Boulder

  • Matthew Glaser

    Physics and Soft Materials Research Center, University of Colorado Boulder, University of Colorado, Boulder, Department of Physics, University of Colorado, Boulder, Institute of Solid State Physics, Otto von Guericke University

  • Joseph E MacLennan

    Physics and Soft Materials Research Center, University of Colorado Boulder, University of Colorado, Boulder, Department of Physics, University of Colorado, Boulder, Physics and Soft Materials Research Center, University of Colorado

  • David M. Walba

    Department of Chemistry, University of Colorado, Boulder

  • Noel Anthony Clark

    Physics and Soft Materials Research Center, University of Colorado Boulder, University of Colorado, Boulder, Department of Physics, University of Colorado, Boulder, Physics and Soft Materials Research Center, University of Colorado