Dresden 2003 – wissenschaftliches Programm
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O: Oberflächenphysik
O 24: Postersitzung (Epitaxie und Wachstum, Oxide und Isolatoren, Elektronische Struktur, Oberfl
ächenreaktionen, Adsorption an Oberfl
ächen, Organische Dünnschichten)
O 24.8: Poster
Mittwoch, 26. März 2003, 14:30–17:30, P1
Growth, Morphology and Stoichiometry of TiOx Films on a Re(10-10) Surface — •Dirk Rosenthal1, Sven L.M. Schroeder1,2, and Klaus Christmann1 — 1Institut für Chemie, Physikalische und Theoretische Chemie, FU Berlin, Takustr. 3, 14195 Berlin — 2Molecular Materials Centre, Department of Chemical Engineering, UMIST, PO Box 88, Manchester, M60 1QD, UK
Titanium oxide films with thicknesses from a few monolayers to multilayers were prepared by co-deposition of titanium and oxygen on a Re(10-10) substrate. The growth, morphology and stoichiometry of these films were characterized by low-energy ion scattering (LEIS), low-energy electron diffraction (LEED) and X-ray photoelectron spectroscopy (XPS). The growth mode of the oxide films changed as a function of temperature, oxygen partial pressure, titanium flux and changing the sequence of titanium and oxygen deposition. The LEIS results reveal that the titanium oxide growth follows a Frank-van-der-Merwe mechanism almost independently of the preparation method. XPS results indicate that deposition at 300 K with an oxygen partial pressure of 10−7 mbar never achieves Ti:O-ratios below 2:3. Stoichiometric titanium dioxide, TiO2, is only afforded at higher substrate temperatures (750K) and by annealing at oxygen partial pressures above 5x10−7mbar. The surface structure of the titanium oxides was examined by LEED and correlated with the individual TiOx-phases.