Kaur, Sarabjot and Panov, V. P. and Greco, C. and Ferrarini, A. and Görtz, Verena and Goodby, John W. and Gleeson, Helen F. (2014) Flexoelectricity in an oxadiazole bent-core nematic liquid crystal. Applied Physics Letters, 105 (22): 223505. pp. 1-4. ISSN 0003-6951
Full text not available from this repository.Abstract
We have determined experimentally the magnitude of the difference in the splay and bend flexoelectric coefficients, |e 1 − e 3|, of an oxadiazole bent-core liquid crystal by measuring the critical voltage for the formation of flexodomains together with their wave number. The coefficient |e 1 − e 3| is found to be a factor of 2–3 times higher than in most conventional calamitic nematic liquid crystals, varying from 8 pCm−1 to 20 pCm−1 across the ∼60 K—wide nematic regime. We have also calculated the individual flexoelectric coefficients e 1 and e 3, with the dipolar and quadrupolar contributions of the bent-core liquid crystal by combining density functional theory calculations with a molecular field approach and atomistic modelling. Interestingly, the magnitude of the bend flexoelectric coefficient is found to be rather small, in contrast to common expectations for bent-core molecules. The calculations are in excellent agreement with the experimental values, offering an insight into how molecular parameters contribute to the flexoelectric coefficients and illustrating a huge potential for the prediction of flexoelectric behaviour in bent-core liquid crystals.