Scanning tunneling microscopy is used to characterize the electronic structure of 1 ML films of c (2×2) NCu (100) (i.e., Cu2 N). By varying nitrogen coverage, a variety of morphologies are prepared, including (1) isolated ∼25 nm2 islands, (2) close-packed arrays of islands, and (3) quasicontinuous monolayer films. In all three regimes, the authors find that Cu2 N acts as an insulator, with a band gap that exceeds 4 eV. The insulating Cu2 N films are used to control the coupling of adsorbed Co atoms to the Cu(100) surface electron density. Tunneling spectroscopy of Co on Cu2 N reveals an unoccupied atomic resonance, Kondo effect, and spin-flip excitation. These features depend on binding site within the Cu2 N film, and are distinctly different than corresponding spectra for Co on Cu(100).
|Number of pages||4|
|Journal||Journal of Vacuum Science and Technology B: Microelectronics and Nanometer Structures|
|State||Published - 2009|