Regensburg 2022 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 66: Oxide Surfaces 2
O 66.4: Vortrag
Donnerstag, 8. September 2022, 11:30–11:45, S053
Structure determination of a dodecagonal oxide quasicrystal — •Sebastian Schenk1, Oliver Krahn1, Holger L. Meyerheim2, Marc De Boissieu3, Stefan Förster1, and Wolf Widdra1 — 1Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, 06120 Halle, Germany — 2Max-Planck-Institut für Mikrostrukturphysik, 06120 Halle, Germany — 3Universite Grenoble Alpes, CNRS, SIMaP, St Martin d Heres, France
The dodecagonal symmetry and the general tiling motive of oxide quasicrystals (OQC) have been proven by electron diffraction (LEED) and scanning tunneling microscopy (STM) from their first observations [1,2]. However, the detailed atomic structure, which includes the decoration of individual tiling elements with metal and oxygen atoms, has been under debate for more than eight years.
In this talk we solve the atomic structure by combination of STM and surface x-ray diffraction (SXRD) of a quasicrystal approximant, which is derived from an ultrathin layer of SrTiO3 on Pt(111). The derived structure model can be generalized for all related ternary oxide quasicrystals and their approximants. The measured diffraction intensities will be compared with calculated ones by lifting the atomic structure of the OQC into its four-dimensional periodic superlattice. These intensities will be compared to SXRD data obtained in synchrotron measurements.
[1] S. Förster et. al., Nature 502, 215 (2013).
[2] S. Schenk et. al., J. Phys.: Condens. Matter 29, 134002 (2017).