| 1. |
- Aksela, S., et al.
(author)
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Accurate free atom-solid binding energy shifts for Au and Ag
- 2012
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In: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048. ; 185:8-9, s. 273-277
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Journal article (peer-reviewed)abstract
- Binding energy shifts between atomic and solid states have been observed with improved accuracy for All 4f and Ag 3d core levels applying a simultaneous measurement method. Also the 3d photoelectron spectrum and binding energies of free Ag atoms have been observed for the first time. New values determined as free atom to bulk solid shifts deviate considerably from previous estimate for Au but agree reasonably well for Ag. The valence bands were also found to shift rather accurately by the same amount as the core levels. (C) 2012 Published by Elsevier B.V.
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| 2. |
- Chernenk, Kirill, et al.
(author)
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Performance and characterization of the FinEstBeAMS beamline at the MAX IV Laboratory
- 2021
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In: Journal of Synchrotron Radiation. - 0909-0495. ; 28, s. 1620-1630
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Journal article (peer-reviewed)abstract
- FinEstBeAMS (Finnish-Estonian Beamline for Atmospheric and Materials Sciences) is a multidisciplinary beamline constructed at the 1.5 GeV storage ring of the MAX IV synchrotron facility in Lund, Sweden. The beamline covers an extremely wide photon energy range, 4.5-1300 eV, by utilizing a single elliptically polarizing undulator as a radiation source and a single grazing-incidence plane grating monochromator to disperse the radiation. At photon energies below 70 eV the beamline operation relies on the use of optical and thin-film filters to remove higher-order components from the monochromated radiation. This paper discusses the performance of the beamline, examining such characteristics as the quality of the gratings, photon energy calibration, photon energy resolution, available photon flux, polarization quality and focal spot size.
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| 3. |
- Fritzsche, S., et al.
(author)
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Photoelectron satellite structure from the 3d and 4d inner-shell ionization of rubidium and cesium: Role of atomic relaxation
- 2008
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In: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 78:3
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Journal article (peer-reviewed)abstract
- The photoelectron satellite structure of rubidium and cesium has been investigated following the photoionization of an nd (n= 3,4) inner-shell electron. The intensity ratios of the nd(-1) ms monopole and nd(-1) m'p conjugated satellite lines have been measured at MAX-lab by using high-resolution electron spectroscopy. For rubidium, moreover, the energy dependence of the 3d(j)6s/3d(j)5s and 3d(j)5p/3d(j)5s intensity ratios with j=3/2 and 5/2 is measured and compared with multiconfiguration Dirac-Fock calculations. A good or at least reasonable agreement is found for both the monopole and conjugated shake-up probabilities if the relaxation of the bound-state electron density is taken into account in the computation of the photoionization cross sections. It is shown that, for the inner-shell ionization of medium and heavy atoms, the orbital relaxation accounts for a significant part of the satellite structure in the photoelectron spectra.
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| 4. |
- Ghosalya, Manoj Kumar, et al.
(author)
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Solar light driven atomic and electronic transformations in a plasmonic Ni@NiO/NiCO3 photocatalyst revealed by ambient pressure X-ray photoelectron spectroscopy
- 2024
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In: Catalysis Science and Technology. - 2044-4753. ; 14:11, s. 3029-3040
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Journal article (peer-reviewed)abstract
- This work employs ambient pressure X-ray photoelectron spectroscopy (APXPS) to delve into the atomic and electronic transformations of a core-shell Ni@NiO/NiCO3 photocatalyst - a model system for visible light active plasmonic photocatalysts used in water splitting for hydrogen production. This catalyst exhibits reversible structural and electronic changes in response to water vapor and solar simulator light. In this study, APXPS spectra were obtained under a 1 millibar water vapor pressure, employing a solar simulator with an AM 1.5 filter to measure spectral data under visible light illumination. The in situ APXPS spectra indicate that the metallic Ni core absorbs the light, exciting plasmons, and creates hot electrons that are subsequently utilized through hot electron injection in the hydrogen evolution reaction (HER) by NiCO3. Additionally, the data show that NiO undergoes reversible oxidation to NiOOH in the presence of water vapor and light. The present work also investigates the contribution of carbonate and its involvement in the photocatalytic reaction mechanism, shedding light on this seldom-explored aspect of photocatalysis. The APXPS results highlight the photochemical reduction of carbonates into -COOH, contributing to the deactivation of the photocatalyst. This work demonstrates the APXPS efficacy in examining photochemical reactions, charge transfer dynamics and intermediates in potential photocatalysts under near realistic conditions.
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| 5. |
- Heinasmaki, S., et al.
(author)
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Distorted angular distribution of the 2p photoelectrons in argon
- 2013
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In: Physica Scripta. - : IOP Publishing. - 0031-8949 .- 1402-4896. ; 87:6
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Journal article (peer-reviewed)abstract
- Two consecutive hemispherical electron energy analyzers have been used to measure the argon angular distribution of 2p photoelectron lines over two quadrants of the dipole plane. A significant anomaly in the intensity of the photolines is observed at several electron emission angles, suggesting asymmetry with respect to the electric field vector of synchrotron light. As a possible cause for the observed behavior, we consider an external field affecting the photoelectrons, and show that it is capable of breaking the left-right asymmetry of the angular distribution, giving rise qualitatively to the observed behavior.
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| 6. |
- Holappa, M., et al.
(author)
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Atom-solid binding energy shifts for K 2p and Rb 3d sublevels
- 2011
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In: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048. ; 184:7, s. 371-374
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Journal article (peer-reviewed)abstract
- Binding energy shifts between free and solid state atoms for K 2p and Rb 3d photolines have been determined by measuring the vapor and solid state spectra simultaneously in similar experimental conditions applying synchrotron radiation excited photoelectron spectroscopy. This method has the important benefit that the work function is not needed to correct for different reference energy levels, therefore much more accurate values for binding energy shifts are obtained. (C) 2011 Elsevier B.V. All rights reserved.
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| 7. |
- Iablonskyi, D., et al.
(author)
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3d photoionization and subsequent decay of atomic gallium
- 2013
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In: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 46:17
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Journal article (peer-reviewed)abstract
- We present an experimental and theoretical study of 3d photoionization and subsequent Auger decay of atomic gallium. The synchrotron radiation-induced electron spectra have been compared and analysed using multiconfiguration Dirac-Fock calculations. It has been shown that the theoretically predicted photoelectron spectrum is in rather good agreement with the experiment allowing us to identify the main spectral features. However, prediction of the Auger decay intensities fails due to calculational difficulties for the continuum wavefunctions of very low kinetic energy Auger electrons.
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| 8. |
- Iablonskyi, D., et al.
(author)
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High resolution study of the inner-shell 3p-3d and 3p-5s resonance regions in calcium atoms
- 2013
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In: Journal of Electron Spectroscopy and Related Phenomena. - : Elsevier BV. - 0368-2048. ; 186, s. 8-13
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Journal article (peer-reviewed)abstract
- The 3p(5)4s(2)3d P-1(1) and 3p(5)(P-2(3/2))4s(2)5s (2)[3/2](1) resonance regions of Ca atoms have been studied experimentally with the aid of synchrotron radiation excited electron spectroscopy. The strong configuration interaction of the 3p(5)4s(2)3d, 3p(5)4s(2)5s and several other nearly degenerate configurations leads to complex structures observed in the photoelectron yield spectrum. Multiconfiguration Dirac-Fock (MCDF) calculations have been performed for these 3p-excited resonances of neutral calcium and compared to experimental results. The excitation and subsequent autoionization of these resonances lead to the final ionic 3p(6)nl states from which new high-lying members of the Rydberg p-series have been resolved experimentally. These new levels agree reasonably well with calculations as well as with the extrapolation of the Rydberg formula. The post collision interaction (PCI) effect has been observed in the transition Ca+ 3p(5)3d4s P-2(1/2,3/2)-> Ca2+ 3p(6) S-1(0) + e(Auger)(-) and explained by means of the rather long core-hole lifetime, while the decay of Ca+ 3p(5)3d4s P-4(1/2),(3/2,5/2) states is not affected by PCI. (c) 2013 Elsevier B.V. All rights reserved.
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| 9. |
- Jankala, K., et al.
(author)
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Analysis of 3d photoionization and subsequent Auger decay of atomic germanium
- 2011
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In: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 84:5
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Journal article (peer-reviewed)abstract
- Experimental and theoretical study of the 3d photoionization and subsequent Auger decay of initially neutral atomic germanium is presented. The features of the high-resolution photoelectron and Auger electron spectra are interpreted with the aid of multiconfiguration calculations. The binding energies and relative cross sections of the 3d ionized fine-structure states of Ge are given. The complete M4,5NN Auger electron spectrum to doubly ionized final states of the Ge ion is interpreted and discussed.
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| 10. |
- Jankala, K., et al.
(author)
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Inner-shell 2p photoionization and Auger decay of atomic silicon
- 2008
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In: Physical Review A (Atomic, Molecular and Optical Physics). - 1050-2947. ; 77:6
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Journal article (peer-reviewed)abstract
- A detailed experiment on 2p photoionization and subsequent Auger decay of atomic silicon is presented. Fine-structure-resolved photoelectron and Auger electron spectra are interpreted with the aid of large-scale multiconfiguration calculations. Energy separation and the relative cross sections of the 2p ionized fine-structure states of Si+ are given. The complete 2p Auger electron spectrum of Si is interpreted, and the intensity distribution to individual doubly ionized final states is studied.
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