Surface-induced orientational phase transition in a lyotropic liquid crystal observed by nonlinear optical techniques

Abstract

We have observed a phase transition from a uniaxial to a biaxial nematic phase in a lyotropic liquid crystal as a function of decreasing film thickness. The results, obtained by optical second-harmonic generation experiments in a wedged cell geometry, are supported by additional [Formula presented]-scan measurements and can be interpreted by wall-induced ordering effects. © 2004 The American Physical Society.