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 degrees 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.

Ferroelectric response and induced biaxiality in the nematic phase of a bent-core mesogen / O., Francescangeli; V., Stanic; S. I., Torgova; Strigazzi, Alfredo; N., Scaramuzza; C., Ferrero; I. P., Dolbnya; T. M., Weiss; R., Berardi; L., Muccioli; S., Orlandi; AND C., Zannoni. - In: ADVANCED FUNCTIONAL MATERIALS. - ISSN 1616-301X. - 19:(2009), pp. 2592-2600. [10.1002/adfm.200801865]

Ferroelectric response and induced biaxiality in the nematic phase of a bent-core mesogen

STRIGAZZI, Alfredo;
2009

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 degrees 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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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/2370146
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