Temperature dependence of the buried glass-smectic liquid crystal interface

We have studied the temperature behavior of the buried Glass-Liquid Crystal Interface for 8CB films of varying thickness deposited into a grated surfa ce, using grazing incidence X-ray scattering. Our results indicate the pres ence of both a chevron structure and a structure similar to the helical twi st-grain-boundary (TGB) phase the evolve as a function of temperature. We f ind that smectic order is preserved at temperatures well above the smectic A - nematic transition, especially in films of intermediate thickness. A de pth analysis of the films indicates that the intensity of the scattering pe ak increases close near the center of the intermediate thickness films. Thi s evolution is accompanied by a rotation of the smectic layers due to flow in the sample.