Berlin 2012 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 58: Poster Session III (Solid/liquid interfaces; Metals; Semiconductors; Oxides and insulators)

O 58.60: Poster

Mittwoch, 28. März 2012, 18:15–21:45, Poster B

Morphology and structure of epitaxial films of TiO_x, BaO_x, and BaTiO₃ on Pt(100) — •Klaus Meinel¹, Stefan Förster¹, Henning Neddermeyer¹, and Wolf Widdra^1,2 — ¹Institute of Physics, Martin-Luther-Universität Halle-Wittenberg, D-06099 Halle, Germany — ²Max-Planck Institut für Mikrostrukturphysik, D-06120 Halle, Germany

Interesting applications are expected for films of ternary oxides with perovskite structure such as BaTiO₃ which display ferroelectric behavior. In previous work of epitaxial BaTiO₃ films on Pt, magnetron sputtering from a BaTiO₃ target has been used for film deposition [1]. In the present work, the more gentile reactive vapor deposition of Ti and BaO in an O₂ atmosphere is used for film preparation. STM, SPA-LEED, AES, and XPS have been applied for investigating morphology, structure, thickness, and composition of the binary oxide (TiO_x and BaO_x) films on Pt(100). After carefully adjusting the deposition rates, the simultaneous growth of both materials yields high quality BaTiO₃(100) films. With respect to Pt(100), their unit mesh is rotated by 45^∘ yielding a misfit of only 2%. Several superstructures develop which are induced by O vacancies. With the calibrated deposition of the oxides of Ti and Ba, in principle, also a layer by layer construction of BaTiO₃ films is possible which allows a deliberate assessment of the interface and surface terminations.

[1] S. Förster, W. Widdra, Surf. Sci. 604, 21631 (2010).