Surface Order in Nematics

Abstract

Interfaces have been studied between a liquid crystal and either glass or an evaporated SiO_X, (60°) layer. Experimental results are discussed from both residual birefringence measurements in the isotropic phase and studies of the influence on the director of an in-plane magnetic field at the phase transition from isotropic to nematic. These data show that on pyrex an ordered interfacial layer exists while on SiO_x (60°) a multidomain structure is present at the surface. Comparison with literature data from nematic phase experiments shows that additional experiments with the isotropic phase and at the phase transition are vital for an understanding of the interfacial phenomena leading to liquid crystal anchorage.