Dresden 2009 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 10: Oxides and insulators II
O 10.2: Vortrag
Montag, 23. März 2009, 15:15–15:30, SCH A01
Growth and atomic structure of epitaxial ultrathin BaTiO3 films on Pt(100) — •Stefan Förster, Michael Huth, Anke Höfer, Karl-Michael Schindler, and Wolf Widdra — Martin-Luther-Universität Halle-Wittenberg, Halle, Germany
Ultrathin BaTiO3(100) films were grown by radio frequency-assisted magnetron sputtering on Pt(100) at room temperature using a Ar/O2 gas mixture at a pressure of 2.5×10−3 mbar. The growth exhibits high reproducibility with respect to film thickness and composition. The Ba/Ti stoichiometry as determined by XPS can be controlled via the gas pressure and the Ar/O2 ratio during deposition. The long-range order of films with perfect BaTiO3 stoichiometry can be improved by post annealing in 1×10−4 mbar O2 at 1000 K. These films show sharp BaTiO3(100)-(1×1) diffraction spots in LEED which allow a LEED-IV analysis in the range of 20 - 400 eV. STM measurements for a 5 ML film reveal a smooth topography with small islands in the top layer. By annealing in oxygen at temperatures above 1050 K a stoichiometric BaTiO3(100)-(4×4) structure is formed.