Regensburg 2013 – scientific programme
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O: Fachverband Oberflächenphysik
O 32: Metal Substrates I
O 32.2: Talk
Tuesday, March 12, 2013, 10:45–11:00, H42
SPALEED and STM studies of the reconstructed Au(100) surface — •Rene Hammer1, Anke Höfer1, Mario Kiel1, Klaus Meinel1, and Wolf Widdra1,2 — 1Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany — 2Max-Planck Institut für Mikrostrukturphysik, D-06120 Halle, Germany
The hexagonal reconstruction of Au(100) has been intensively studied over more than four decades [1]. Nevertheless, some issues regarding the toplayer to substrate matching and alignment, respectively, are ambiguously reported. We quantitatively reinvestigated the system by combining the high resolving powers of SPALEED and STM. A Au(100) sample of excellent quality was used showing after cleaning two types of perfect c(26x48) superstructure domains. They are generated by the buckling of quasihexagonal toplayers which are characterized by lattice vectors having the length of 0.9575a and 0.9630a, respectively, where a is the interatomic distance of Au(100). The former vectors exactly run along [011] or [01-1] whereas the latter ones deviate by 120.19∘ from that directions. Ar+ ion bombardment at elevated temperatures induced a rotation of the toplayers up to angles of ± 0.89∘. Sample annealing yields a turning back into the initial toplayer alignment. The reorientation proceeds continuously, i.e. all angles between ± 0.89∘ are observed.
[1] D.G. Fedak and N.A. Gjostein, Surf. Sci. 8 (1967) 77; M.A. Van Hove et al., Surf. Sci. 103 (1983) 189; G.K. Binnig et al., Surf. Sci. 144 (1984) 321; P. Havu et al., Phys. Rev. B 82 (2010) 161418(R).