Regensburg 2016 – scientific programme
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O: Fachverband Oberflächenphysik
O 89: Oxides and Insulator Surfaces II
O 89.5: Invited Talk
Thursday, March 10, 2016, 16:00–16:30, H4
The growth and decay of oxide quasicrystals — •Stefan Förster1, Jan Ingo Flege2, Eva Maria Zollner1, Florian Schumann1, Klaus Meinel1, Jens Falta2, and Wolf Widdra1,3 — 1Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, Halle, Germany — 2Institute of Solid State Physics, University of Bremen, Bremen, Germany — 3Max Planck Institute of Microstructure Physics, Halle, Germany
Two-dimensional materials have recently pioneered a new field of materials science. Their peculiar properties are often related to their lower dimensional periodic structure. A new member in this class of materials are two-dimensional oxide quasicrystals (OQC)[1]. Here I will present the first in-situ high-temperature characterization of the BaTiO3-derived OQC. This OQC develops in a 2D wetting layer spreading from 3D BaTiO3 islands on Pt(111) and exhibits a sharp twelvefold diffraction pattern [1]. The structure formation process includes the growth of an amorphous wetting layer which can either develop further into the OQC or into long-range ordered periodic structures, the so-called approximants. Insights into this process are derived from combining the findings of scanning tunneling microscopy (STM) and low-energy electron diffraction (LEED) measurement with in-situ low-energy electron microscopy (LEEM) studies. Besides the details of the quasicrystalline growth process, the in-situ LEEM and µ-LEED studies reveal also the high-temperature stability of this new phase.
[1] S. Förster, K. Meinel, R. Hammer, M. Trautmann, and W. Widdra, Nature 502, 215 (2013).