Orientation of individual C 60 molecules adsorbed on Cu(111): Low-temperature scanning tunneling microscopy and density functional calculations

摘要: Density functional theory (DFT) and low-temperature scanning tunneling microscopy (STM) have been combined to examine the bonding of individual ${\mathrm{C}}_{60}$ molecules on Cu(111). Energy-resolved differential-conductance maps measured for adsorbed a Cu(111) surface by means STM, which are compared complemented theoretically computed spectral images. It has found that chemisorbs with six-membered ring parallel at two different binding sites constitute exclusive hexagonal sublattices. On each sublattice, is bonded in one particular rotational conformer, i.e., bind azimuthal orientations differing 60\ifmmode^\circ\else\textdegree\fi{} depending sublattice site belongs to. The conformation its orientation regard copper can be deduced this joint experimental-theoretical approach. Six possible pairs configurations three Cu identified fulfil requirements sublattices consistent all experimental theoretical data. Theory proposes these configuration most likely. We DFT does not get energy between conformers correct order. also report monolayers Cu(111): alternating neighboring low temperature other $(4\ifmmode\times\else\texttimes\fi{}4)$ structure after annealing above room temperature.