| 1. |
- CHAKAROV, DV, et al.
(författare)
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INTERACTION OF WATER WITH POTASSIUM ON GRAPHITE - A HREELS STUDY
- 1993
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Ingår i: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048 .- 1873-2526. ; 64-5, s. 279-285
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Tidskriftsartikel (refereegranskat)abstract
- Water and coadsorbed water + potassium on the basal plane of graphite were studied with high resolution electron energy loss spectroscopy (HREELS) at 85 K and after stepwise annealing up to 500 K. Water adsorbs non-dissociatively on both clean and potassium precovered surface at 85 K. The vibration spectra, together with thermal desorption spectroscopy (TDS) reveal a series of reactions within the coadsorbed layer leading to the formation of KOH, KH, and KOx and volatile products. Eventually a precursor to CO2 formation, of yet unindentified composition and observed also in K + O-2 coadsorption studies on graphite, is observed at approximate to 27 meV.
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| 2. |
- CHAKAROV, DV, et al.
(författare)
-
PHOTOSTIMULATED DESORPTION OF METAL ADATOMS - POTASSIUM ON GRAPHITE
- 1994
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Ingår i: Surface Science. - : Elsevier BV. - 0039-6028 .- 1879-2758. ; 311:3, s. L724-L730
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Tidskriftsartikel (refereegranskat)abstract
- Photodesorption is observed of single K atoms from a graphite surface covered with less than 1 monolayer of potassium. The desorption cross section has a threshold at homegaBAR almost-equal-to 3 eV and a maximum at homega(max)BAR almost-equal-to 4.9 eV. Polarization measurements indicate a substrate-mediated mechanism. The coverage dependence suggests that only the ionic 2D, K-phase is photoactive. The proposed mechanism includes attachment of hot electrons, photoexcited in the bulk, to the K4s adsorbate resonance of energy E(res). The band structure of graphite causes a narrow energy distribution of hot electrons, which yields homega(max)BAR almost-equal-to 2E(res).
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