Dresden 2003 – wissenschaftliches Programm

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O: Oberflächenphysik

O 38: Struktur und Dynamik reiner Oberfl
ächen

O 38.5: Vortrag

Freitag, 28. März 2003, 12:15–12:30, FOE/ANOR

Deep going reconstruction of Ir(100)-(5×1) — •Andreas Schmidt, Wolfgang Meier, Andreas Klein, Lutz Hammer und Klaus Heinz — Festkörperphysik, Universität Erlangen-Nürnberg, Staudtstr. 7, D-91058 Erlangen

The reconstructed (5×1)-phase of Ir(100) has been reinvestigated by quantitative low-energy electron diffraction (LEED) though the type of the surface reconstruction, namely a top layer in quasi-hexagonal atomic arrangement with some buckling induced in the second layer, is known since long. Extension of the LEED analysis to higher electron energies than before (600 eV) shows that such bucklings extend with considerable amplitude into the surface even to the fourth layer. We show that this new information comes by the increased surface penetration provided by the higher electron energies, so that the scattering contribution of deeper layers is increased. Additionally, the error limits for the structural parameters determined are reduced. One the one hand, this is due to the increased data base, i. e.  the total energy width of accumulated I(E) spectra, which leads to a smaller variance of the Pendry R-Factor. On the other hand, the average wavelength of the surface probing electrons is smaller, which allows for a higher precision as mirrored by a steeper R-factor hyperface. This applies for all layer parameters varied, independent of the layer depth.