Electro-optical Kerr effect data have been obtained for 6CB, 6CHBT, 6PCH and 6BOBT at temperatures above the nematic-isotropic transition temperature. All the compounds had a positive Kerr constant which increased with decreasing of temperature. The second order phase transition temperatures, T*, were determined for these compounds. The linear dependence of (T - T*)-1 on the Kerr constant is found to be relatively in good agreement with the predications of the Landau-De Gennes model. The replacement of aromatic ring by a flexible cyclohexyl group and or by a bulkier bicyclooctane has a marked effect on the birefringence. Hexyl 4-(4-isothiocyanato-phenyl) bicycle [2,2,2] octane, 6BOBT, with the highest transition temperature had the lowest Kerr constant. In contrast, hexyl cyanobiphenyl,6CB, showed the largest Kerr constant (6BOBT → 6CHBT ≈ 6PCH → 6CB). The effect of the rigid core and polar head group of the liquid crystals was investigated.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.