3A12 Orientational Formation of Liquid Crystalline Films Evaporated on the Treated Surfaces : Evaluation by Improved Maximum Entropy Method based on Surface Second Harmonic Generation and Polarized UV Absorption

Abstract

We have investigated the molecular orientation formation of 5CB liquid crystalline films evaporated on a rubbed surface and a photoaligned surface composed of photoisomerizable alignment layer. The molecular orientational distributions evaluated by improved maximum entropy method, based on not only SHG results (3^<rd> order parameters) but also polarized UV absorption results (2^<nd> order parameters), show distinct difference between two treated surfaces ; the alignment axis of 5CB at rubbed surface begins to tilt up from the surface plane as the molecular density increases, while the alignment axis of 5CB at photoaligned surface remains on the surface plane eyen when the molecular density increases.