The initial stages of Cr and Ti growth on SiO2(0001)
| Autor: | S.A. Haycock, A.P. Woodhead, V.R. Dhanak, S.P. Harte, Christopher A. Muryn, Paul L. Wincott, G. Thornton, C.E. Marsden, S. Vinton, T.M. Evans |
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| Rok vydání: | 1999 |
| Předmět: |
Materials science
Inorganic chemistry Oxide chemistry.chemical_element Crystal growth Surfaces and Interfaces Condensed Matter Physics Surfaces Coatings and Films Metal Crystallography Chromium chemistry.chemical_compound Lattice constant chemistry Transition metal Rutile visual_art Materials Chemistry visual_art.visual_art_medium Titanium |
| Zdroj: | Surface Science. 424:179-186 |
| ISSN: | 0039-6028 |
| DOI: | 10.1016/s0039-6028(98)00882-6 |
| Popis: | The initial stages of titanium growth on the 1×1 and ( 84 × 84 ) R11° terminations and chromium growth on the ( 84 × 84 ) R11° termination of α-quartz SiO2 (0001) have been studied using polarization-dependent SEXAFS. Three metal coverages have been examined: nominally 0.25, 0.5 and 1.0 ML. The Ti K-edge results evidence reduction of the selvedge through the formation of a titanium oxide; with metallic Ti clusters formed at higher coverages. Ti–O distances of 1.96–2.00±0.03 A are observed along with Ti–Ti distances of 2.89–2.92±0.03 A. The former range is close to the Ti–O bond distances in rutile, whereas the latter is within the experimental error of that of bulk titanium. The Cr K-edge results are consistent with the formation of 15 atom clusters having an average nearest-neighbour Cr–Cr distance of 2.36±0.03 A. This represents a contraction of about 6% from the bulk bcc lattice spacing. Such a contraction is consistent with the prediction of recent calculations. |
| Databáze: | OpenAIRE |
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