title: Influence of an external field on the surface tension of free-standing smectic films.
abstract: We have carried out a theoretical study of the effect of the electric field E on the thermodynamical properties and surface tension γ of free-standing smectic films. Calculations, based upon the extended McMillan approach with anisotropic forces, show a stepwise reduction and increase of the values of the Helmholtz free energy f and γ, respectively, per partially fluorinated 5-n-alkyl-2-[4-n-(perfluoroalkyl-metheleneoxy)phenyl] (H10F5MOPP) molecule, as the temperature is raised above that for the bulk smectic-A-isotropic transition. Calculations show that E may not only affect the layer-thinning transition sequence, but also change the first multilayer jump in the thickness and increase the value of γ per H10F5MOPP molecule. Reasonable agreement between the theoretically predicted and the experimentally obtained data on γ of the partially fluorinated H10F5MOPP film has been obtained.
authors.affiliation: Saint Petersburg Institute for Machine Sciences, The Russian Academy of Sciences, Saint Petersburg 199178, Russia. avz0911@yahoo.com
authors.forename: A V
authors.initials: AV
authors.lastname: Zakharov
authors.forename: A A
authors.initials: AA
authors.lastname: Vakunenko