Regensburg 2016 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 87: Metal Substrates: Structure, Epitaxy and Growth
O 87.5: Vortrag
Donnerstag, 10. März 2016, 16:15–16:30, S053
The surface reconstruction of Pt(001) revisited — Rene Hammer1, Oliver Krahn1, Klaus Meinel1, and •Wolf Widdra1,2 — 1Martin-Luther-Universität Halle-Wittenberg, Halle, Germany — 2Max-Planck Institut für Mikrostrukturphysik, Halle, Germany
The complex hexagonal reconstruction of the (001) surfaces of platinum and gold is under debate since decades [1,2]. In the present study, we combine SPA-LEED and STM together with LEED simulations based on a Moiré approach to address the Pt(001) reconstruction. Smooth samples annealed at 900∘C show two domains of a c(26x128±10) superstructure. The superstructure evolves from a Moiré-like buckling of a quasi-hexagonal top layer (hex). The lattice vectors of the hex are reduced to 0.9606a and 0.9629a with respect to the interatomic distance a of Pt(001). The former runs exactly along [011] or [011] whereas the latter one deviates by 120.08∘ from that directions. Sample annealing at 1000 ∘C stimulates a continuous rotation of the hex where all angles between 0 and ± 0.8∘ are simultaneously realized. At 1100∘C, the hex resides in fixed rotation angles of ±(0.77∘ ± 0.01∘). Sputtering at elevated temperatures lowers the value n of the c(26x2n) superstructure down to 34 and leads to a continuous rotation in the range of ±0.8∘. In many aspects, the Pt(001) reconstruction displays a similar behavior as found for Au(001) [2].
[1] P. Havu et al., Phys. Rev. B 82 (2010) 161418(R) and references therein;
[2] R. Hammer et al. Phys. Rev. B 90 (2014) 035446.