Berlin 2005 – wissenschaftliches Programm

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O: Oberflächenphysik

O 15: Postersitzung (Adsorption an Oberfl
ächen, Epitaxie und Wachstum, Organische Dünnschichten, Oxide und Isolatoren, Rastersondentechniken, Zeitaufgelöste Spektroskopie, Methoden)

O 15.49: Poster

Freitag, 4. März 2005, 17:00–20:00, Poster TU D

Surface and Interface Structures of ZrO₂(111) Films on Pt(111) — •K. Meinel¹, A. Eichler², K.-M. Schindler¹, H. Neddermeyer¹, and W. Widdra¹ — ¹Martin-Luther-Universität Halle-Wittenberg, FB Physik, D-06099 Halle, Germany — ²Institut für Materialphysik und Center for Computational Material Science, Universität Wien, Sensengasse 8/12, A-1090 Wien, Austria

ZrO₂ films are prepared on Pt(111) by reactive deposition of Zr in an O₂ atmosphere followed by post-annealing and characterized by STM, LEED and DFT calculations. After deposition, the films display a slightly rotated p(1 × 1) structure. Post-annealing of submonolayer films yields ZrO₂ films having a slightly compressed (4 × 4) structure, which is commensurate to a (5 × 5) structure of the Pt(111) interface. Post-annealing of thicker films yields a (2 × 2) structure, which is slightly expanded and commensurate to a (√7 × √7) structure of the Pt(111) interface. Continuing the annealing induces the formation of domains possessing a ( 1 × 1 ) structure rotated by ± 6.6^∘. These domains are energetically favored and grow at the expense of the (2 × 2) areas. With the film rotation, a (3 √3 × 3 √3) film structure develops, which is slightly compresssed and commensurate to a rotated ( √19 × √19) R ± 36.6^∘ structure of the Pt(111) interface. High temperature annealing ( T > 1200 K) finally yields incommensurate structures of expected Zr_xO_yPt_z phases.