ORIENTATION OF A SOLID PARTICLE EMBEDDED IN A MONODOMAIN NEMATIC LIQUID-CRYSTAL

A problem of the equilibrium orientation of an elongated solid particl e put inside a uniformly aligned nematic liquid crystal is studied. Th e particle is assumed to be sufficiently large so that the orientation al distortions it causes may be treated in the framework of the contin uum theory. Three kinds of anchoring of nematic material on the partic le surface are considered: two of the planar, and one of the homeotrop ic type. We prove that, depending on the anchoring strength, the stabl e orientation of the particle major axis may be either perpendicular ( weak anchoring) or parallel (strong anchoring) to the unperturbed dire ctor of the liquid-crystalline domain. The dimensionless parameter con trolling the situation is the ratio omega of the transverse size of th e particle to the extrapolation length of the nematic material. The tr ansition from the perpendicular to the parallel orientation of the par ticle takes place at omega approximately 1.