A theory of temperature dependent switching transition in mixed liquid crystals of opposite diamagnetic anisotropies

Abstract

A Landau type theory of the switching transition observed as a function of temperature in mixed liquid crystals of opposite diamagnetic anisotropies is presented. The theory is also extended to explain the nematic to isotropic transition of the mixture, which occurs at another critical temperature. The theory explains experimental results for the mixture N-(p-ethoxybenzylidene)-p-n-butylaniline (EBBA) and a ternary eutectic mixture of propyl, pentyl and heptyl bicyclohexyl carbonitrile (ZLI-1167) obtained by NMR using a probe molecule such as acetonitrile. The agreement between the theoretical and experimental results is satisfactory.