Ferroelectric Response and Induced Biaxiality in the Nematic Phase of Bent‐Core Mesogens |
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| Authors: | Oriano Francescangeli Vesna Stanic Sofia I Torgova Alfredo Strigazzi Nicola Scaramuzza Claudio Ferrero Igor P Dolbnya Thomas M Weiss Roberto Berardi Luca Muccioli Silvia Orlandi Claudio Zannoni |
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| Affiliation: | 1. Dipartimento di Fisica e Ingegneria dei Materiali e del Territorio and CNISM Università Politecnica delle Marche Via Brecce Bianche, 60131 Ancona (Italy);2. P.N. Lebedev Physical Institute of the Russian Academy of Sciences Leninsky Pr. 53, Moscow, 119991 (Russia);3. Dipartimento di Fisica and CNISM, Politecnico di Torino C.so Duca degli Abruzzi 24, 10129 Torino (Italy);4. LiCryl (CNR‐INFM) and CEMIF.CAL, Dipartimento di Fisica Università degli Studi della Calabria Ponte P. Bucci C 31C, 87036 Rende, Cosenza (Italy);5. European Synchrotron Radiation Facility Bo?te Postale 220, 38043 Grenoble Cedex (France);6. Present address: Diamond Light Source, Rutherford Appleton Laboratory, Chilton, Didcot, OX11 0QX, UK;7. Present address: Stanford Synchrotron Radiation Laboratory, Menlo Park, CA 94025, USA;8. Dipartimento di Chimica Fisica e Inorganica and INSTM CRIMSON Università di Bologna Viale del Risorgimento 4, 40136 Bologna (Italy) |
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| Abstract: | The still undiscovered fluid ferroelectric nematic phase is expected to exhibit a much faster and easier response to an external electric field compared to conventional ferroelectric smectic liquid crystals; therefore, the discovery of such a phase could open new avenues in electro‐optic device technology. Here, experimental evidence of a ferroelectric response to a switching electric field in a low molar mass nematic liquid crystal is reported and connected with field‐induced biaxiality. The fluid is made of bent‐core polar molecules and is nematic over a range of 120 °C. Combining repolarization current measurements, electro‐optical characterizations, X‐ray diffraction and computer simulations, ferroelectric switching is demonstrated and it is concluded that the response is due to field‐induced reorganization of polar cybotactic groups within the nematic phase. This work represents significant progress toward the realization of ferroelectric fluids that can be aligned at command with a simple electric field. |
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| Keywords: | cybotactic groups electro‐optic devices ferroelectricity nematic biaxiality theoretical simulations x‐ray diffraction |
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