WALLS OF ORIENTATION INDUCED IN SEMATIC-LIQUID-CRYSTAL SAMPLES BY INHOMOGENEOUS SURFACES

A theoretical analysis of the walls of orientation induced in nematic liquid crystal by inhomogeneous surfaces is presented. The case in whi ch the nematic liquid crystals may be approximated by a semiinfinite m edium is considered for different kinds of inhomogeneities. The same a nalysis is extended to a slab of nematic liquid crystal of definite th ickness. The influence of the thickness of the sample on the width of the wall of orientation is evaluated in the frame of strong- and weak- anchoring situations. The threshold field for the Freedericksz effect for nematic samples characterized by uniform easy axis but nonuniform anchoring energy on the experimental determination of the anchoring en ergy strength is discussed.