A NEW CONFIGURATIONAL TRANSITION IN INHOMOGENEOUS NEMATICS

At the wall in a hybrid cell with strong anchoring, the nematic direct or is parallel to one wall and perpendicular to the other. Usually, th e free energy is minimized by a configuration where the director orien tation changes continuously with position across the cell. The boundar y conditions can also be satisfied, however, by a biaxial configuratio n without such rotation. Under certain conditions, such as under incre ased curvature strains, a transition can take place between these conf igurations. The transition typically occurs when the wavelength of the deformation becomes comparable to the coherence length of the materia l. The hybrid cell considered is a simple illustrative example, in rea l systems, such a transition may be expected in highly strained thermo tropics, or in strained lyotropics which are easily made biaxial.