FREEDERICKSZ TRANSITIONS IN SMECTIC LIQUID-CRYSTALS IN ANNULAR GEOMETRIES

This paper investigates the stability of simple static orientation pat terns in a sample of smectic liquid crystal confined to a cylindrical annulus, when a magnetic field is applied. Four different arrangements are considered, covering cases where the layer normal is everywhere e ither radial or axial, and the (orthogonal) magnetic field is either r adial, azimuthal or axial. A classification is given of the threshold radii for mechanical instabilities, and of the threshold magnetic fiel ds for Freedericksz transitions for these cases, with strong anchoring at the boundaries.