Berlin 2015 – wissenschaftliches Programm
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O: Fachverband Oberflächenphysik
O 4: Electronic Structure of Surfaces I
O 4.3: Vortrag
Montag, 16. März 2015, 11:00–11:15, MA 041
Angle-resolved ultraviolet photoemission spectroscopy of quasicrystalline BaTiO3 films on Pt(111) — •Richard Kraska1, Konrad Gillmeister1, Stefan Förster1, Eva Maria Zollner1, Klaus Meinel1, Cheng-Tien Chiang2,1, and Wolf Widdra1,2 — 1Institut für Physik, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany — 2Max-Planck-Institut für Mikrostrukturphysik, Halle, Germany
Bulk BaTiO3 is a widely investigated perovskite. As recently discovered, thin films of this material can form a long-range ordered, quasicrystalline structure on the hexagonal Pt(111) surface with 12-fold rotational symmetry. Although the two-dimensional structure has been investigated by STM, LEED and XPS [1], no information on the electronic valence band structure has been reported so far. Here we present angle-resolved photoelectron spectroscopy data along the [121] and [110] directions of the substrate for a well-ordered quasicrystalline BaTiO3-derived film using a photon energy of 21.22 eV. Comparing the data from the quasicrystalline film and from the clean platinum substrate, we can identify a weakly dispersive feature at 6 eV below the Fermi level that is assigned to the aperiodic structure.
[1] S. Förster, K. Meinel, R. Hammer, M. Trautmann, and W. Widdra, Nature 502, 215 (2013)