| 1. |
- O'Shea, JN, et al.
(författare)
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Hydrogen-bond induced surface core-level shift in isonicotinic acid
- 2001
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Intermolecular hydrogen-bonding in thick films of isonicotinic acid evaporated onto rutile TiO2(110) has been investigated with X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS). The rate of deposition is found to be a key fac
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| 2. |
- O'Shea, JN, et al.
(författare)
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Hydrogen-bond induced surface core-level shift in pyridine carboxylic acids
- 2001
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Ingår i: SURFACE SCIENCE. - : ELSEVIER SCIENCE BV. - 0039-6028. ; 486:3, s. 157-166 Language: English
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Tidskriftsartikel (refereegranskat)abstract
- Intermolecular hydrogen bonding in thick films of pyridine carboxylic acids (isonicotinic; picolinic and bi-isonicotinic acid) evaporated onto rutile TiO2(1 1 0) has been investigated with X-ray photoelectron spectroscopy and X-ray absorption spectroscopy
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| 3. |
- O'Shea, JN, et al.
(författare)
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X-ray photoelectron spectroscopy of low surface concentration mass-selected Ag clusters
- 2000
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Ingår i: JOURNAL OF CHEMICAL PHYSICS. - : AMER INST PHYSICS. - 0021-9606. ; 113:20, s. 9233-9238
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Tidskriftsartikel (refereegranskat)abstract
- We have developed an experimental setup for the study of small mass-selected clusters delivered by soft landing to a model oxide support. An automated deposition system to achieve accurately quantified homogeneous surfaces is described which also overcome
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| 4. |
- Schiessling, J, et al.
(författare)
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Insulating surface layer on single crystal K3C60
- 2004
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Ingår i: European Physical Journal B. Condensed Matter and Complex Systems. - : Springer Science and Business Media LLC. - 1434-6028. ; 41:4, s. 435-438
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Tidskriftsartikel (refereegranskat)abstract
- Using angle-dependent photoemission spectra of core and valence levels we show that metallic, single crystal K3C60 is terminated by an insulating or weakly-conducting surface layer. We attribute this to the effects of strong intermolecular correlations combined with the average surface charge state. Several controversies on the electronic structure are thereby resolved.
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| 5. |
- Schnadt, J, et al.
(författare)
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Alignment of valence photoemission, x-ray absorption, and substrate density of states for an adsorbate on a semiconductor surface
- 2003
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Ingår i: Physical Review B (Condensed Matter and Materials Physics). - 1098-0121. ; 67:23
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Tidskriftsartikel (refereegranskat)abstract
- A method for determining the placement of x-ray absorption data into an experimental density of states for an adsorbate-semiconductor system is motivated and illustrated with the cases of bi-isonicotinic acid, isonicotinic acid, and benzoic acid on rutile TiO2(110). Special attention is paid to experimental aspects, as well as the role of Z+1 effects and the choice of reference level.
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| 6. |
- Schnadt, J, et al.
(författare)
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Excited-state charge transfer dynamics in systems of aromatic adsorbates on TiO2 studied with resonant core techniques
- 2003
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Ingår i: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 119:23, s. 12462-12472
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Tidskriftsartikel (refereegranskat)abstract
- Resonant core spectroscopies are applied to a study of the excited electron transfer dynamics on a low-femtosecond time scale in systems of aromatic molecules (isonicotinic acid and bi-isonicotinic acid) adsorbed on a rutile TiO2(110) semiconductor surface. Depending on which adsorbate state is excited, the electron is either localized on the adsorbate in an excitonic effect, or delocalizes rapidly into the substrate in less than 5 fs (3 fs) for isonicotinic acid (bi-isonicotinic acid). The results are obtained by the application of a variant of resonant photoemission spectroscopy. (C) 2003 American Institute of Physics.
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| 7. |
- Schnadt, Joachim, et al.
(författare)
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Structural study of adsorption of isonicotinic acid and related molecules on rutile TiO2(110) I: XAS and STM
- 2003
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Ingår i: Surface Science. - 0039-6028. ; 540:1, s. 39-54
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Tidskriftsartikel (refereegranskat)abstract
- X-ray absorption spectroscopy (XAS) and scanning tunneling microscopy (STM) have been used to study the absorption of monolayers of the pyridinecarboxylic acid monomers (isonicotinic acid, nicotinic acid, and picolinic acid) and benzoic acid on a rutile TiO2(1 1 0) surface. We find that the pyridine and phenyl rings are oriented with their planes largely perpendicular to the surface. The azimuthal orientations are strongly influenced by adsorbate-adsorbate interactions, which in each case leads to at least two different molecular species. In order to reach this conclusion a detailed strategy has been developed for the interpretation of angle-dependent XAS data, which does not rely on any curve fitting procedures. (C) 2003 Elsevier B.V. All rights reserved.
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| 8. |
- Schnadt, J, et al.
(författare)
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Structural study of adsorption of isonicotinic acid and related molecules on rutile TiO2(110) II: XPS
- 2003
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Ingår i: Surface Science. - : Elsevier BV. - 0039-6028. ; 544:1, s. 74-86
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Tidskriftsartikel (refereegranskat)abstract
- The adsorption of monolayers of the pyridine-carboxylic acid monomers (isonicotinic acid, nicotinic acid, and picolinic acid) on rutile TiO2(1 1 0) has been studied by means of X-ray photoemission spectroscopy. An investigation of the O 1s spectra shows that the molecular carboxylic groups are deprotonated and, hence, that the molecules bind to the surface in a bidentate mode. Moreover, the binding energy of those core levels that are related to the pyridine ring atoms shift as a function of molecule relative to the substrate O 1s and Ti 3p levels, while the position of the core levels related to emission from the carboxylic group are constant relative to the substrate levels. The molecule-dependent shifts are attributed to local intermolecular interactions that determine the proximity of adjacent molecular rings and thus the core-hole screening response of the neighbouring molecules. We propose a simple molecular arrangement for each case which satisfies the known constraints. (C) 2003 Elsevier B.V. All rights reserved.
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