Kinetic energy distributions of C+, , Au+, AuC+ and emitted from a gold surface following single impact of keV : Carbide ions formation via a recombination mechanism
✍ Scribed by Y. Cohen; E. Kolodney
- Publisher
- Elsevier Science
- Year
- 2011
- Tongue
- English
- Weight
- 379 KB
- Volume
- 269
- Category
- Article
- ISSN
- 0168-583X
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✦ Synopsis
We have studied the formation and emission of small carbide cluster ions AuC + and AuC þ 2 following reactive ion shattering of 10 keV C À 60 on gold. We have measured kinetic energy distributions of several outgoing cations (C + , C þ 2 , Au + , AuC + and AuC þ 2 ) and found pronounced differences between these of the carbon fragments ions and carbide ones, with broad C + , C þ 2 distributions peaking at $11 eV and much narrower AuC + , AuC þ 2 distributions peaking at $2-3 eV. Density functional theory calculations of the AuC þ 2 cation have shown that the two most stable isomer structures are composed of a carbon dimer strongly bound to a gold ion. Analysis of the kinetic energy distributions transformed into speed distributions, together with the calculated structures, suggest that the formation of the carbide cluster ions (AuC + , AuC þ
2 ) is via a recombination between independently emitted, moving gold and carbon species, within the surface vicinity.