Observation and Structure Determination of an Oxide Quasicrystal Approximant.
We report on the first observation of an approximant structure to the recently discovered two-dimensional oxide quasicrystal. Using scanning tunneling microscopy, low-energy electron diffraction, and surface x-ray diffraction in combination with ab initio calculations, the atomic structure and the bonding scheme are determined. The oxide approximant follows a 3^{2}.4.3.4 Archimedean tiling. Ti atoms reside at the corners of each tiling element and are threefold coordinated to oxygen atoms. Ba atoms separate the TiO_{3} clusters, leading to a fundamental edge length of the tiling 6.7 Å.
Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.
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Förster
Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.
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Trautmann
Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany.
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Roy
Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.
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Adeagbo
Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.
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Zollner
Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.
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Hammer
Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.
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Schumann
Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.
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Meinel
Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.
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Nayak
Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany.
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Mohseni
Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.
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Hergert
Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany.
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Meyerheim
Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany.|Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany.
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Widdra