The static Kerr effect of two nematic mixtures comprised of pentyl and heptyl cyanobiphenyls in the isotropic phase

Electro-optic Kerr effect and the pretransition behaviour was investigated for the 5CB and two of pentyl and heptyl nematic mixtures, (F1 [71% 5CB:29% 7CB] and F2 [51% 5CB:49% 7CB]), at temperatures above the nematic-isotropic transition temperature. The Kerr constant of these liquid crystals was found to be very high at the nematic-isotropic transition temperatures. The linear dependence of (T-T*)(-1) on the Kerr constant is found to be in good agreement with the predications of the Landau-De Gennes model. (C) 2003 Elsevier B.V. All rights reserved.