ausblenden:
Schlagwörter:
-
Zusammenfassung:
The structure of silicon surfaces in the orientation range (113)–(5,5,12)–(337)–(112) has been investigated using high resolution LEED and photoemission both on a spherical and on flat samples. We find that Si(5,5,12) [5.3° from (113) and 0.7° from (337)] is the only stable orientation between (113) and (111) and confirm the result of Baski et al. [Science 269, 1556 (1995)] that it has a 2×1 superstructure with a very large unit cell of 7.68×53.5 Å2. Adsorption measurements of water on Si(5,5,12) yield a mobile precursor kinetics with two kinds of regions saturating at 0.25 and 0.15 ML which are related to adsorption on different sites. Using these results, a modified structure model is proposed. Surfaces between (113) and (5,5,12) separate into facets of these two orientations; between (5,5,12) and (112), they separate into (5,5,12) and (111) facets. (337) facets in this range may be considered as defective (5,5,12) facets.
