title: Crystal growth of para-sexiphenyl on clean and oxygen reconstructed Cu(110) surfaces.
abstract: The formation of crystalline para-sexiphenyl (6P) films on Cu(110) and Cu(110)-(2 × 1)O (Cu-O) has been studied by low energy electron diffraction, X-ray absorption spectroscopy and both in situ and ex situ X-ray diffraction methods to elucidate the transition from the initial monolayers to crystalline thin films. It is found that, for Cu-O, a single and, for Cu(110), a double wetting layer is formed which then acts as a template for the subsequent 3D crystal growth. For both substrates the orientation of the long molecular axes of the 6P molecules in the first layers is conserved for the molecules in the bulk crystals growing on them. The main difference between both systems is that on Cu-O the first monolayer assembles in a form close to that of a 6P bulk plane which can be easily continued by crystallites grown upon them, while on the Cu(110) surface the 6P mono- and bi-layers differ substantially from the bulk structure. The bi-layer forms a complex periodically striped phase. Thin 6P films grow with the 6P(203) crystal plane parallel to the Cu-O substrate surface. For this orientation, the 6P molecules are stacked in layers and the molecules demonstrate only one tilt of the mean molecular plane with respect to the sample surface. On clean Cu(110), a more complex 6P(629) plane is parallel to the substrate surface and this orientation is likely a consequence of the super-molecular long-range periodicity of the second molecular layer striped phase.
authors: Institute of Solid State Physics, Graz University of Technology, Petersgasse 16, Graz 8010, Austria.
authors: Jiří
authors: J
authors: Novák
authors: Martin
authors: M
authors: Oehzelt
authors: Stephen
authors: S
authors: Berkebile
authors: Markus
authors: M
authors: Koini
authors: Thomas
authors: T
authors: Ules
authors: Georg
authors: G
authors: Koller
authors: Thomas
authors: T
authors: Haber
authors: Roland
authors: R
authors: Resel
authors: Michael G
authors: MG
authors: Ramsey
mesh_terms: D003300:Copper / Q000737:chemistry*; D003460:Crystallization; D008567:Membranes, Artificial; D010100:Oxygen / Q000737:chemistry*; D010316:Particle Size; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D008567:Membranes, Artificial; D011084:Polycyclic Aromatic Hydrocarbons; C533755:p-sexiphenyl; D003300:Copper; D010100:Oxygen