# Smectic-A Order at the Surface of a Nematic Liquid Crystal: Synchrotron X-Ray Diffraction

 Title: Smectic-A Order at the Surface of a Nematic Liquid Crystal: Synchrotron X-Ray Diffraction Author: Als-Nielsen, J.; Christensen, F.; Pershan, Peter S. Note: Order does not necessarily reflect citation order of authors. Citation: Als-Nielsen, J., F. Christensen, and Peter S. Pershan. 1982. Smectic-A order at the surface of a nematic liquid crystal: Synchrotron x-ray diffraction. Physical Review Letters 48(16): 1107–1110. Full Text & Related Files: Als-Nielsen_Smectic.pdf (747.0Kb; PDF) Abstract: A novel geometry in which it is possible to do x-ray diffraction from a horizontal surface of fluids is applied to liquid crystals. A large-diameter drop of octyloxycyanobiphenyl (8OCB) on a glass plate treated for homeotropic alignment yields perfect alignment of the smectic-A layers at the top surface over an area of several square millimeters. The surface in the bulk nematic as well as in the isotropic phase was found to consist of smectic-A layers with a penetration depth equal to the longitudinal smectic-A correlation length $$\xi_{\parallel} \sim (T-T_{NA})^{-\nu_{\parallel}}$$ determined previously. Published Version: doi:10.1103/PhysRevLett.48.1107 Terms of Use: This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAA Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:10361859 Downloads of this work: