Eur. Phys. J. B 6, 83-91 (1998)
https://doi.org/10.1007/s100510050529

Azimuthal anchoring of nematic on undulated substrate: Elasticity versus memory

¹ Unità INFM di Cosenza, Dipartimento di Fisica, Università della Calabria, 87036 Rende, Italy
² Laboratoire de Physique des Solides, Université Paris-Sud, Bâtiment 510, 91405 Orsay Cedex, France
³ Institute of Solid State Physics, Bulgarian Academy of Sciences, 72 blvd. Tsarigradsko Chaussee, 1784 Sofia, Bulgaria
⁴ INCDFM - Magurele C.P. MG-7, 76900 Bucharest, Romania

Corresponding author: ^a dozov@lps.u-psud.fr

Received: 29 April 1998
Accepted: 23 June 1998
Published online: 15 November 1998

Abstract

We measure the azimuthal anchoring energy of the nematic 5CB on sinusoidal holographic unidimensional and bidimensional gratings. We find that the anchoring strength is almost the same for all of the gratings and up to one order of magnitude stronger than expected by the topographic mechanism proposed by Berreman. We observe strong memory effects which dominate both the elastic anchoring and the easy axis gliding. We show that these memory effects limit from below the anchoring energy and are the main obstacle in the realization of substrates with weak anchoring conditions.