The optical retardation of a liquid crystal above the nematic-isotropic phase transition temperature TNI and subjected to planar alignment conditions Show moreThe optical retardation of a liquid crystal above the nematic-isotropic phase transition temperature TNI and subjected to planar alignment conditions at the substrate was investigated in the presence of an electric field applied normal to the substrates. The response was found to exhibit "S"-shaped behavior with electric field, and was larger near TNI than well above TNI. The results were examined in the context of a model that permits both biaxiality and a field-induced tilt of the molecular director. The results suggest that the primary effect of the electric field is to induce biaxiality, and in consequence suppress the order induced by the surface. No clear indication of a Freedericksz-like transition, either experimental or theoretical, was observed. Appropriate bibliographic citation and notice of the APS copyright must be included- "Kim J.-H., Petschek R.G., Rosenblatt C., Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics 60:0.208333333333333, 5600-5606 (1999). Copyright 1999 by the American Physical Society." Show less