title: Morphology of open films of discotic hexagonal columnar liquid crystals as probed by grazing incidence X-ray diffraction.
abstract: The structure and the orientation of thermotropic hexagonal columnar liquid crystals are studied by grazing incidence X-ray diffraction (GIXD) for different discotic compounds in the geometry of open supported thin films. Whatever the film deposition mode (either spin-coating or vacuum evaporation) and the film thickness, a degenerate planar alignment with the liquid crystalline columns parallel to the substrate is found. However, if a specific thermal process is applied to the liquid crystal film, homeotropic anchoring (columns normal to the interface) can be stabilized in a metastable state.
authors.affiliation: Centre de Recherche Paul-Pascal, CNRS -Université de Bordeaux, 115 Avenue Schweitzer, 33600, Pessac, France. grelet@crpp-bordeaux.cnrs.fr
authors.forename: Eric
authors.initials: E
authors.lastname: Grelet
authors.forename: Sébastien
authors.initials: S
authors.lastname: Dardel
authors.forename: Harald
authors.initials: H
authors.lastname: Bock
authors.forename: Michel
authors.initials: M
authors.lastname: Goldmann
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Lacaze
authors.forename: Frédéric
authors.initials: F
authors.lastname: Nallet
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