Details
| Original language | English |
|---|---|
| Pages (from-to) | 87-97 |
| Number of pages | 11 |
| Journal | Surface Science |
| Volume | 517 |
| Issue number | 1-3 |
| Publication status | Published - 22 Jul 2002 |
Abstract
Electron stimulated desorption of oxygen atoms from the surface of epitaxially grown MgO films on Ag(1 0 0) produces characteristic losses of color centers in electron energy loss spectroscopy. The formation of five distinct loss features at 1.0, 1.3, 2.4, 2.8 and 3.4 eV have been observed that are induced by electron bombardment of the MgO surface. The possibility to erase these losses completely by simple exposure to O2 gas at room temperature suggests that they are predominantly located at or near the surface. From the dependence of loss intensities on electron exposure we conclude that the defects are generated directly by the electron impingement. The observed losses are tentatively assigned to electronic transitions associated with surface F centers (Fs) located at differently coordinated sites (surface, steps) and to M-centers. The characteristic steps of the cross-section at electron energies of 55 and 86 eV, which are close to binding energies of the Mg 2p and 2s energy levels in MgO, suggest a desorption mechanism via a multi-electron Auger decay process.
Keywords
- Electron energy loss spectroscopy (EELS), Magnesium oxides, Surface defects
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Materials Science(all)
- Surfaces, Coatings and Films
- Materials Science(all)
- Materials Chemistry
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In: Surface Science, Vol. 517, No. 1-3, 22.07.2002, p. 87-97.
Research output: Contribution to journal › Article › Research › peer review
}
TY - JOUR
T1 - Mechanism and kinetics of color center formation on epitaxial thin films of MgO
AU - Kramer, J.
AU - Ernst, W.
AU - Tegenkamp, Christoph
AU - Pfnür, Christoph
PY - 2002/7/22
Y1 - 2002/7/22
N2 - Electron stimulated desorption of oxygen atoms from the surface of epitaxially grown MgO films on Ag(1 0 0) produces characteristic losses of color centers in electron energy loss spectroscopy. The formation of five distinct loss features at 1.0, 1.3, 2.4, 2.8 and 3.4 eV have been observed that are induced by electron bombardment of the MgO surface. The possibility to erase these losses completely by simple exposure to O2 gas at room temperature suggests that they are predominantly located at or near the surface. From the dependence of loss intensities on electron exposure we conclude that the defects are generated directly by the electron impingement. The observed losses are tentatively assigned to electronic transitions associated with surface F centers (Fs) located at differently coordinated sites (surface, steps) and to M-centers. The characteristic steps of the cross-section at electron energies of 55 and 86 eV, which are close to binding energies of the Mg 2p and 2s energy levels in MgO, suggest a desorption mechanism via a multi-electron Auger decay process.
AB - Electron stimulated desorption of oxygen atoms from the surface of epitaxially grown MgO films on Ag(1 0 0) produces characteristic losses of color centers in electron energy loss spectroscopy. The formation of five distinct loss features at 1.0, 1.3, 2.4, 2.8 and 3.4 eV have been observed that are induced by electron bombardment of the MgO surface. The possibility to erase these losses completely by simple exposure to O2 gas at room temperature suggests that they are predominantly located at or near the surface. From the dependence of loss intensities on electron exposure we conclude that the defects are generated directly by the electron impingement. The observed losses are tentatively assigned to electronic transitions associated with surface F centers (Fs) located at differently coordinated sites (surface, steps) and to M-centers. The characteristic steps of the cross-section at electron energies of 55 and 86 eV, which are close to binding energies of the Mg 2p and 2s energy levels in MgO, suggest a desorption mechanism via a multi-electron Auger decay process.
KW - Electron energy loss spectroscopy (EELS)
KW - Magnesium oxides
KW - Surface defects
UR - http://www.scopus.com/inward/record.url?scp=0036783906&partnerID=8YFLogxK
U2 - 10.1016/S0039-6028(02)01966-0
DO - 10.1016/S0039-6028(02)01966-0
M3 - Article
AN - SCOPUS:0036783906
VL - 517
SP - 87
EP - 97
JO - Surface Science
JF - Surface Science
SN - 0039-6028
IS - 1-3
ER -