title: Binding of single gold atoms on thin MgO(001) films.
abstract: In the present Letter the first electron paramagnetic resonance spectra of single metal atoms on a single crystalline oxide surface are presented. For Au atoms on a MgO(001) film investigated here an analysis of the angular dependent resonance positions and the hyperfine coupling to (17)O shows that the atoms are bound on top of oxygen ions on the terrace of the film. This result is in perfect agreement with scanning tunneling microscopy measurements at 5 K presented here. The measured hyperfine matrix components allow an experimental verification of the theoretically proposed binding mechanism of Au atoms on MgO. In particular, the large reduction of the isotropic hyperfine coupling constant of supported Au as compared to free atoms is not due to a charge transfer at the interface but a hybridization of orbitals and a resulting polarization of the unpaired electron.
authors.affiliation: Department of Chemical Physics, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, D-14195 Berlin, Germany.
authors.forename: Maxim
authors.initials: M
authors.lastname: Yulikov
authors.forename: Martin
authors.initials: M
authors.lastname: Sterrer
authors.forename: Markus
authors.initials: M
authors.lastname: Heyde
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Rust
authors.forename: Thomas
authors.initials: T
authors.lastname: Risse
authors.forename: Hans-Joachim
authors.initials: HJ
authors.lastname: Freund
authors.forename: Gianfranco
authors.initials: G
authors.lastname: Pacchioni
authors.forename: Andrea
authors.initials: A
authors.lastname: Scagnelli