Morphology change of oxygen-restructuredTiO2(110)surfaces by UHV annealing: Formation of a low-temperature(1×2)structure
| Autor: | Wilhelm Hebenstreit, Ulrike Diebold, Min Li |
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| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | Physical Review B. 61:4926-4933 |
| ISSN: | 1095-3795 0163-1829 |
| DOI: | 10.1103/physrevb.61.4926 |
| Popis: | When reduced ${\mathrm{TiO}}_{2}(110)$ single crystals are oxidized at moderate temperatures (470--660 K), the surfaces restructure. Interstitial Ti atoms from the bulk diffuse to the surface where they react with gaseous oxygen and form new, added ${\mathrm{TiO}}_{2}$ layers. These are characterized by three structural elements: small $(1\ifmmode\times\else\texttimes\fi{}1)$ islands, irregular networks of pseudohexagonal rosettes, and [001]-oriented strands. The strands exhibit the same structural characteristics as the $(1\ifmmode\times\else\texttimes\fi{}2)$ surface reconstruction, which forms upon annealing at higher temperatures. Atomic-resolution scanning tunneling microscopy images of the strands are consistent with the added-${\mathrm{Ti}}_{2}{\mathrm{O}}_{3}$-row model. UHV annealing of oxygen-restructured surfaces smooths the surfaces and converts the rosette networks into strands and finally into regular $(1\ifmmode\times\else\texttimes\fi{}1)$ terraces. The composition of these oxygen-induced phases is quantified using ${}^{18}{\mathrm{O}}_{2}$ gas in combination with low-energy ${\mathrm{He}}^{+}$ ion scattering measurements. Dynamic processes for the conversion from rosette networks into $(1\ifmmode\times\else\texttimes\fi{}2)$ strands and ultimately into $(1\ifmmode\times\else\texttimes\fi{}1)$ terraces are discussed. |
| Databáze: | OpenAIRE |
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