Dresden 2003 – scientific programme
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TT: Tiefe Temperaturen
TT 6: Postersitzung I (Amorphe- u. Tunnelsysteme, Niedrigdimensionale Systeme, Supraleitung: Elektronenstruktur, Phononen, Tunneln, Ordnungsparameter)
TT 6.11: Poster
Monday, March 24, 2003, 14:30–19:00, P2c, P2d
Structural and electronic properties of submonolayer coverages of Au on vicinal Si(111) — •Maya Schöck1, Svenja Klages1, Christoph Sürgers1, and Hilbert v. Löhneysen1,2 — 1Physikalisches Institut und DFG Center for Functional Nanostructures, Universität Karlsruhe, D-76128 Karlsruhe — 2Forschungszentrum Karlsruhe, Institut für Festkörperphysik, D-76021 Karlsruhe
Chainlike surface structures are observed after evaporation of submonolayer coverages of Au on Si(111) miscut by 10∘ towards the <112> direction. This Si(557):Au surface is controversally discussed due to its unusual electronic properties found in various angular resolved photoemission spectroscopy experiments.
In this work, scanning tunneling microscopy and spectroscopy have been performed to investigate the local structural and electronic properties of this surface. Tunneling spectra taken on or off the distinct chainlike structures exhibit strong differences due to the lateral variation of the local surface density of states. The spectra are compared to recent theoretical band-structure calculations. In addition, electronic transport measurements have been performed in situ for temperatures T= 1.8 − 300 K. In all cases studied, the electrical resistance measured with the current running along the chainlike structures exhibits an increase with decreasing temperature, i.e. non-metallic behaviour is found. Several possible reasons for this behaviour, such as activated hopping between segments of chains, are discussed.