High pressure measurements of the refractive indices of two nematic liquid crystals

Abstract

The refractive indices of two nematogens, 4-methoxy-benzylidene-4'-n-butyl-aniline (MBBA) and 4-n-pentyl-4'-cyanobiphenyl (5CB), have been measured throughout their nematic ranges at pressures up to 2 kbar and temperatures up to 70 °C in the first substance and up to 5 kbar and 145 °C in the second. Measurements were made at λ = 5 890 Å, using a sensitive interference fringe technique. Results are presented in the form of functions n e(P, T) for the extraordinary index and no (P, T) for the ordinary index, obtained by least squares fits to the experimental data