| Autor: |
Krischok, S., Stracke, P., Kempter, V. |
| Předmět: |
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| Zdroj: |
Applied Physics A: Materials Science & Processing; Jan2006, Vol. 82 Issue 1, p167-173, 7p, 4 Graphs |
| Abstrakt: |
MgO films (2-nm thick) were grown on W(110) while metastable impact electron (MIES) and photoelectron (UPS(HeI)) spectra were collected in situ; apart from the valence-band emission no additional spectral features could be detected. The oxide surface was exposed to metal atoms (Cu; Pd) (substrate at 300 K). For Cu, but not for Pd/MgO, a characteristic initial decrease of the surface work function by about 0.4 eV is observed for small exposures. Metal-induced intensity develops above the top of the O2p valence band in UPS caused by 3dCu (4dPd) emission. The emission seen for Cu/MgO in the MIES spectra above the 2pO valence band is attributed to the ionization of Cu4s states of neutrally adsorbed Cu species; the shape of the MIES spectra suggests island growth even at the lowest studied exposures. For Cu/MgO the critical coverage for the transition from 2D to 3D island growth, as determined with MIES, is estimated as 0.15 monolayers. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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