| 1. |
- Giovanelli, L., et al.
(författare)
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Synchrotron radiation photoelectron spectroscopy study of Pb-Pc thin films on InSb(100)-(4x2)/c(8x2)
- 2001
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Ingår i: Surface Science. - 0039-6028 .- 1879-2758. ; 486:02-jan, s. 55-64
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Tidskriftsartikel (refereegranskat)abstract
- The electronic properties and the thermal stability of a thin film of lead-phthalocyanine deposited on the InSb(100)-(4 x 2)/c(8 x 2) surface were studied by synchrotron radiation core level and valence band photoelectron spectroscopy. The interaction between the overlayer and the substrate was determined by analyzing the photoemission spectra of a thin film and of a single monolayer of adsorbed molecules. Subsequently the monolayer was annealed at increasing temperatures, leading first to a gradual change of the oxidation state of the central lead atom, then to a fragmentation of the macrocycle itself.
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| 2. |
- Sinner-Hettenbach, M., et al.
(författare)
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Electronic structure of SnO2(110)-4 x 1 and sputtered SnO2(110) revealed by resonant photoemission
- 2002
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Ingår i: Surface Science. - 0039-6028 .- 1879-2758. ; 499:1, s. 85-93
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Tidskriftsartikel (refereegranskat)abstract
- The surface properties of SnO2(1 1 0)-4 x 1 and sputtered SnO2(1 1 0) were studied comparatively by resonant photoemission of the valence band states in a photon energy range of 60-130 eV. Resonating energetic levels could be observed on the 4 x I reconstructed surface and the resonance behavior could be switched off by sputter treatment. Additionally, the Sn 4d core-levels were recorded at two photon energies in order to allow a statement about the surface's stoichiometry. A tentative explanation of the observed resonance and of the discrepancy between ordered and sputtered surface is given with regard to recent STM results on similar prepared surfaces.
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| 3. |
- Sinner-Hettenbach, M., et al.
(författare)
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High resolution photoemission study on SnO2 gas sensors
- 2001
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Ingår i: Thin Solid Films. - 0040-6090 .- 1879-2731. ; 391:2, s. 192-197
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Tidskriftsartikel (refereegranskat)abstract
- Pd-, Pt-doped and undoped SnO2 gas sensors were studied by synchrotron radiation photoelectron spectroscopy (SRPES) and laboratory source UPS (ultraviolet photoelectron spectroscopy). Valence band spectra were recorded for photon energies of 60-120 eV (SRPES) and for 40.81 eV (UPS). The spectra were analyzed by factor analysis and generation of difference spectra. A comparison of the samples shows that the doping material of these sensors is not introducing additional states to the surface electronic structure within the limit of detection. This leads to the conclusion that the surfaces of the grains are not enriched with the metal additives.
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| 4. |
- Sinner-Hettenbach, M., et al.
(författare)
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Oxygen-deficient SnO2(110) : a STM, LEED and XPS study
- 2001
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Ingår i: Surface Science. - 0039-6028 .- 1879-2758. ; 477:1, s. 50-58
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Tidskriftsartikel (refereegranskat)abstract
- The reconstruction process of SnO2(110) was investigated by scanning tunneling microscopy (STM), low energy electron diffraction (LEED) and X-ray photoelectron spectroscopy (XPS). The high-temperature 1 x 1 reconstruction could be identified as an intermediate face, transferable either to the 1 x 2 surface by annealing to higher temperature or back to the 4 x 1 reconstruction by annealing again at lower temperature. In this way, a new method to prepare well-ordered 4 x 1 terminated surfaces is introduced and the O/Sn ratio as well as the core-level positions of Sn 3d and O 1s were traced by XPS over a temperature range of 700-1200 K on freshly sputtered and on low-temperature long-time annealed SnO2(110). STM images of the 1 x 1 surface show a new structure of in-plane oxygen, ordered locally in zigzag rows that contribute to the LEED pattern as a very diffuse 2 x 1 intensity.
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