title: Planar anchoring and surface melting in the smectic-A phase.
abstract: We study ultrathin films of 8CB in planar anchoring on a MoS2 inorganic substrate. We evidence an anchoring breakage for 60-nm-thick films, in favor of the homeotropic anchoring at the air interface. This allows one to determine the 8CB-MoS2 smectic anchoring energy. We then demonstrate for films thinner than 60 nm that, under the homeotropic bulk, an intermediate film remains in planar anchoring, associated with a melting of the smectic layers close to the substrate. Such a melting could be general for planar or tilted anchorings and we show that, for strong anchorings, the anchoring energy can be driven by the deformations of this intermediate nematic film.
authors.affiliation: INSP, CNRS UMR-7588, Universités Pierre et Marie Curie-Paris 6, 140 Rue de Lourmel, F-75015 Paris, France. emmanuelle.lacaze@insp.jussieu.fr
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Lacaze
authors.forename: Jean-Philippe
authors.initials: JP
authors.lastname: Michel
authors.forename: Michel
authors.initials: M
authors.lastname: Alba
authors.forename: Michel
authors.initials: M
authors.lastname: Goldmann