Eur. Phys. J. E (2019) 42: 78
https://doi.org/10.1140/epje/i2019-11842-7

Regular Article

Structural and optical properties of free-standing smectic films

¹ Poznan University of Economics and Business, Department of Mathematical Economics, Al. Niepodleglosci 10, 61-875, Poznan, Poland
² Saint Petersburg Institute for Machine Sciences, The Russian Academy of Sciences, 199178, Saint Petersburg, Russia

^* e-mail: izabela.sliwa@ue.poznan.pl
^** e-mail: alexandre.zakharov@yahoo.ca

Received: 4 December 2018
Accepted: 22 May 2019
Published online: 24 June 2019

Abstract

We have carried out a complex numerical study of the structural, thermodynamic and optical properties of the partially fluorinated 5-n -alkyl-2-(4-n-(perfluoroalkyl-metheleneoxy)phenyl) free-standing smectic film in air under the action of the external electric field . Calculations, based upon the extended McMillan’s mean-field theory with anisotropic forces, show a stepwise reduction of the value of the Helmholtz free energy and the reflectivity of the partially fluorinated smectic film in air, as the temperature is raised above the bulk smectic-A-isotropic transition value. It has been shown, by solving the self-consistent nonlinear equations for the orientational and translational order parameters, that the electric field may not only affect the layer-thinning transition sequences, but also change the first multilayer jump in the film thickness, whereas practically does not affect the reflectivity R(N) of the partially fluorinated N -layer smectic film in air. In the range of film thicknesses investigated, the reduction of the R(N) is, at least, qualitatively in agreement with the experimentally observed decrease of the optical reflectivity with the decrease of N.