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 molarmass 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.
Ferroelectric response and induced biaxiality in the nematic phase of a bent-core mesogen / O. Francescangeli; V. Stanic; S.I. Torgova; A. Strigazzi; N. Scaramuzza; C. Ferrero; I. Dolbnya; T. M. Weiss; R. Berardi; L. Muccioli; S. Orlandi; C. Zannoni. - In: ADVANCED FUNCTIONAL MATERIALS. - ISSN 1616-301X. - STAMPA. - 19:(2009), pp. 2560-2592. [10.1002/adfm.200801865]
Ferroelectric response and induced biaxiality in the nematic phase of a bent-core mesogen
BERARDI, ROBERTO;MUCCIOLI, LUCA;ORLANDI, SILVIA;ZANNONI, CLAUDIO
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 molarmass 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.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.