Regensburg 2004 – wissenschaftliches Programm

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O: Oberflächenphysik

O 3: Nanostrukturen I

O 3.5: Vortrag

Montag, 8. März 2004, 12:15–12:30, H36

Sandwich-like nanowire formation on Ir(100) — •Andreas Klein, Chiara Giovanardi, Andreas Schmidt, Lutz Hammer, and Klaus Heinz — Lehrstuhl für Festkörperphysik , Universität Erlangen-Nürnberg, Staudtstr. 7, D-91058 Erlangen

As shown recently [1], the stable quasi-hexagonal (5×1) reconstruction of the clean Ir(100) surface restructures by exposure to hydrogen. The new phase corresponds to a lateral superlattice of almost defect-free monoatomic Ir nanowires arranged on the unreconstructed, i.e. (1×1)-symmetric substrate. The average lateral spacing of the wires is 1.36 nm and their length in the range of micrometers. Investigations by scanning tunnelling microscopy (STM) and low-energy electron diffraction (LEED) show that this hydrogen-induced phase of Ir(100) can be used as a template to produce other nanostructures. So, deposition of e.g. iron leads to the decoration of both sides of the Ir wires. Hereby, the Fe atoms occupy fourfold-symmetric substrate sites. This corresponds to the formation of FeIrFe sandwich-like nanowires which are as perfect as the original Ir wires. At 0.4 ML Fe coverage the new phase is equivalent to a vacancy spaced lateral {FeIrFe} superlattice. Its crystallographic structure has been analyzed by quantitative LEED.

[1] L. Hammer, W. Meier, A. Klein, P. Landfried, A. Schmidt, and K. Heinz, Phys. Rev. Lett. 91 (2003) 156101