Real time observation of ultrathin epitaxial oxide growth during alloy oxidation
- Author(s)
- Andreas Stierle, R Streitel, P Nolte, A Vlad, Ioan Costina, Martijn Marsman, Georg Kresse, Edvin Lundgren, Jesper N. Andersen, R Franchy, Helmut Dosch
- Abstract
We have studied the thermal oxidation of the intermetallic alloy CoGa in situ, in real time on the atomic scale, during the growth of an ultrathin, epitaxial Ga oxide layer. On the basis of an extended set of surface x-ray diffraction data, density functional theory calculations and core level spectroscopy data, we find that the oxide film consists of an oxygen ion double layer, which contains the basic building block of bulk ?-Ga 2O3. The oxide formation takes place via the nucleation of two-dimensional, anisotropic oxide islands which laterally grow and coalesce. A dramatic increase of the oxide island size is observed for low O2 pressures in the 10-8 mbar regime, which we interpret as the onset of a step flow like growth mode. This allows us to conclude that thermal oxidation can be considered as a hetero-epitaxial growth process, that follows similar atomistic growth principles to molecular beam epitaxy. As a consequence, the structural perfection of the oxide layer can be tailored by the appropriate choice of oxygen pressure and temperature. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
- Organisation(s)
- Computational Materials Physics
- External organisation(s)
- Max-Planck-Institut für Metallforschung, Technische Universität Wien, Lund University, Forschungszentrum Jülich
- Journal
- New Journal of Physics
- Volume
- 9
- No. of pages
- 8
- ISSN
- 1367-2630
- DOI
- https://doi.org/10.1088/1367-2630/9/9/331
- Publication date
- 2007
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 1030 Physics, Astronomy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/47d43e04-2a2e-442e-84a7-0727b6585561