| 1. |
- Bjorneholm, O, et al.
(author)
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Femtosecond dissociation of core-excited HCl monitored by frequency detuning
- 1997
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In: PHYSICAL REVIEW LETTERS. - : AMER INST PHYSICS. - 0031-9007. ; 79:17, s. 3150-3153
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Journal article (other academic/artistic)abstract
- Core excitation of gaseous HCl to the dissociative sigma* state leads to a deexcitation spectrum with two qualitatively different contributions-a broad molecular background and narrow atomic lines. The experiment demonstrates that the ratio of integrated
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| 2. |
- Gisselbrecht, Mathieu, et al.
(author)
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Photon energy dependence of fragmentation of small argon clusters
- 2005
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In: Journal of Chemical Physics. - : AIP Publishing. - 0021-9606 .- 1089-7690. ; 123:19
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Journal article (peer-reviewed)abstract
- Photofragmentation of small argon clusters with size below ten atoms is reported. In this size range significant modifications from the electronic properties and geometry take place. When tuning the photon energy through the argon 2p edge, the fragmentation pattern is changed. Specifically, cation dimer production is enhanced at the 2p(3/2)-> 4s resonance, while above the 2p edge almost complete atomization is observed. In both cases, the widths of the peaks in the mass spectra indicate that a large amount of kinetic energy is imparted to the fragment due to the formation of multiply charged clusters. A model based on "Coulomb explosion"-charge separation, simply resulting in a complete atomization of the cluster with no dependence on the photon energy-is insufficient to explain the observed photofragmentation of small clusters.
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| 3. |
- Kivimäki, A, et al.
(author)
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Resonant Auger spectroscopy of argon clusters at the 2p threshold
- 2005
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In: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 71:3
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Journal article (peer-reviewed)abstract
- Resonant Auger spectra of large argon clusters have been measured at the Ar 2p edge. The decay spectra can give some information on the states reached in photon absorption. For example, the observation of the 3p(4)4p final states indicates the occurrence of the 2p(3/2)-> 4p excitation in clusters, whereas in atoms this excitation is dipole forbidden. Also the 3p(4)3d final states are identified in the resonant Auger spectra. A peculiar finding is that the normal Auger transitions in bulk cluster atoms are observed below the 2p ionization thresholds. This is explained by the excitation of the 2p electrons into the conduction band, followed by a rapid delocalization of the electron.
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| 4. |
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| 5. |
- Ohrwall, G, et al.
(author)
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Observation of elastic scattering effects on photoelectron angular distributions in free Xe clusters
- 2003
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In: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 36:19, s. 3937-3949
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Journal article (peer-reviewed)abstract
- We report an observation of substantial deviations in the photoelectron angular distribution for photoionization of atoms in free Xe clusters compared to the case of photoionization of free atoms. The cross section, however, seems not to vary between the cluster and free atoms. This observation was made in the vicinity of the Xe 4d Cooper minimum, where the atomic angular distribution is known to vary dramatically. The angular distribution of electrons emitted from atoms in the clusters is more isotropic than that of free atoms over the entire kinetic energy range studied. Furthermore, the angular distribution is more isotropic for atoms in the interior of the clusters than for atoms at the surface. We attribute this deviation to elastic scattering of the outgoing photoelectrons. We have investigated two average cluster sizes, (N) approximate to 4000 and 1000 and found no significant differences between these two cases.
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| 6. |
- Sundin, S, et al.
(author)
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Auger decay of core-excited higher Rydberg states of carbon monoxide
- 1997
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In: JOURNAL OF PHYSICS B-ATOMIC MOLECULAR AND OPTICAL PHYSICS. - : IOP PUBLISHING LTD. - 0953-4075. ; 30:19, s. 4267-4278
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Journal article (other academic/artistic)abstract
- The de-excitation of higher core-excited C 1s(-1)np Rydberg states of carbon monoxide has been studied. It is found that already with a main quantum number of 4 or higher, Rydberg states of p-symmetry can be successfully treated within the single-particle
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| 7. |
- Tchaplyguine, Maxim, et al.
(author)
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Selective probing of the electronic structure of free clusters using resonant core-level spectroscopy
- 2003
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In: Chemical Physics. - 0301-0104. ; 289:1, s. 3-13
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Journal article (peer-reviewed)abstract
- In this paper the first resonant photoemission and partial electron yield studies of free clusters are presented. The resonant photoemission spectra of free argon clusters have been recorded with excitation energies determined from the cluster X-ray absorption spectrum near the Ar 2p ionization threshold. The decay of 2p(-1)4s and 2p(-1)3d cluster surface and "bulk" excited states has been investigated in detail. The combination of resonant photoemission and partial electron yield methods has allowed a selective probing of the electronic and geometric structure, yielding new results concerning the interplay between the energy of the excited states, their orbital character and the local atomic coordination. These new results demonstrate the power of resonant core level spectroscopy when applied to free clusters, as well as the advantages of free clusters for the studies of the bulk and surface energetics of nanoscale solids. (C) 2002 Elsevier Science B.V. All rights reserved.
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