Abstract
Ultra-thin titania films were grown on a Mo(1 1 0) substrate by vapor depositing Ti in an O2 ambient (5 × 10-7 Torr) at 600 K, followed by annealing to 900-1200 K. X-ray photoelectron spectroscopy showed that titanium oxide films annealed to 900 K were partially reduced, exhibiting Ti4+, Ti3+ and Ti2+ species, whereas films annealed to 1200 K were fully oxidized and exhibited only Ti4+. Corresponding scanning tunneling microscopy measurements revealed layer-by-layer growth of titania films on Mo(1 1 0) at 900 K. Flat terraces with three different orientations were observed. The line spacings between the neighboring atomic rows for all terraces were ∼6.5 Å, suggesting epitaxial growth of TiO2(1 1 0)-(1 × 1). A further anneal of the films to 1200 K led to three-dimensional, rough surfaces for the fully oxidized films, indicating the formation of stable crystallites at high temperature.
Original language | English |
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Pages (from-to) | 1-8 |
Number of pages | 8 |
Journal | Surface Science |
Volume | 487 |
Issue number | 1-3 |
DOIs | |
Publication status | Published - 2001 Jul 20 |
Externally published | Yes |
Bibliographical note
Funding Information:We acknowledge with pleasure the support of this work by the Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences and the Robert A. Welch Foundation. We thank Charles C. Chusuei for his comments and discussion.
Keywords
- Growth
- Molybdenum
- Scanning tunneling microscopy
- Titanium oxide
- X-ray photoelectron spectroscopy
ASJC Scopus subject areas
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry