Change search
Refine search result
1 - 9 of 9
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Katayama, T.
    et al.
    Anniyev, T.
    Beye, M.
    Coffee, R.
    Dell'Angela, M.
    Foehlisch, A.
    Gladh, Jörgen
    Stockholm University, Faculty of Science, Department of Physics.
    Kaya, S.
    Krupin, O.
    Nilsson, Anders
    Stockholm University, Faculty of Science, Department of Physics. SLAC National Accelerator Laboratory, USA.
    Nordlund, D.
    Schlotter, W. F.
    Sellberg, Jonas A.
    Stockholm University, Faculty of Science, Department of Physics. SLAC National Accelerator Laboratory, USA.
    Sorgenfrei, F.
    Turner, J. J.
    Wurth, W.
    Östrom, Henrik
    Stockholm University, Faculty of Science, Department of Physics.
    Ogasawara, H.
    Ultrafast soft X-ray emission spectroscopy of surface adsorbates using an X-ray free electron laser2013In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 187, p. 9-14Article in journal (Refereed)
    Abstract [en]

    We report on an experimental system designed to probe chemical reactions on solid surfaces on a sub-picosecond timescale using soft X-ray emission spectroscopy at the Linac Coherent Light Source (LCLS) free electron laser (FEL) at the SLAC National Accelerator Laboratory. We analyzed the O 1s X-ray emission spectra recorded from atomic oxygen adsorbed on a Ru(0001) surface at a synchrotron beamline (SSRL, BL13-2) and an FEL beamline (LCLS, SXR). We have demonstrated conditions that provide negligible amount of FEL induced damage of the sample. In addition we show that the setup is capable of tracking the temporal evolution of electronic structure during a surface reaction of submonolayer quantities of CO molecules desorbing from the surface.

  • 2.
    Leetmaa, Mikael
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Ljungberg, Mathias
    Stockholm University, Faculty of Science, Department of Physics.
    Lyubartsev, Alexander
    Stockholm University, Faculty of Science, Department of Physics.
    Nilsson, Anders
    Stockholm University, Faculty of Science, Department of Physics.
    Pettersson, Lars G.M.
    Stockholm University, Faculty of Science, Department of Physics.
    Theoretical Approximations to X-ray Absorption Spectroscopy of Liquid Water and Ice2010In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 177, no 2-3, p. 135-157Article in journal (Refereed)
    Abstract [en]

    We review methods to compute x-ray absorption spectra (XAS) with special focus on the transition potential approach of Triguero et al. [Phys. Rev. B 58, 8097 (1998)] and its application to calculations on water in condensed phase. We discuss the absolute energy scale, functional dependence, broadening versus sampling of intra- and intermolecular vibrational modes, treatment of the continuum, cluster size convergence as well as compare with periodic calculations and with experiment; periodic and cluster model calculations are found to agree very closely in the relevant near-edge region although neither reproduces the pre-edge and main-edge features in the experimental spectra of thin ice films. The real space grid representation of the wave function in the periodic calculations allows a more extended energy range to be described and we find satisfactory agreement with experiment for higher energy continuum resonances. Two proposed alternative approaches using either the potential from a full core-hole (FCH) or the full core-hole with an excited electron in the lowest state (XCH) are shown to lead to spectra that deviate significantly from experiment.

  • 3.
    Liljequist, David
    Stockholm University, Faculty of Science, Department of Physics.
    Contribution from inelastic scattering to the validity of trajectory methods2013In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 189, p. 5-11Article in journal (Refereed)
    Abstract [en]

    Previous calculations of elastic particle scattering in clusters of randomly distributed point scatterers have shown that Monte Carlo trajectory simulation may be valid as an approximation of quantum multiple elastic scattering, provided that the particle wavelength is about equal to or smaller than the average distance between nearest neighbour scatterers. For the biologically important case of electrons in liquid water, this suggests that trajectory simulation of multiple elastic scattering may be valid (less than 5% error) for electron energies down to about 15 eV. Short range order increases the error somewhat, and produces, as well known, manifest diffraction effects under single scattering conditions. Present similar calculations show that trajectory simulation may be a reasonably good approximation also for particles with wavelengths substantially larger than d(nn), if plural or multiple inelastic scattering is introduced. This suggests that for electrons in liquid water trajectory simulation might, depending on the nature and frequency of inelastic scattering, be valid as an approximation at electron energies as low as a few eV.

  • 4.
    Nilsson, Anders
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Nordlund, D.
    Waluyo, I.
    Huang, N.
    Ogasawara, H.
    Kaya, S.
    Bergmann, U.
    Naeslund, L. -A
    Öström, Henrik
    Stockholm University, Faculty of Science, Department of Physics.
    Wernet, Ph.
    Andersson, K. J.
    Stockholm University, Faculty of Science, Department of Physics.
    Schiros, Theanne
    Stockholm University, Faculty of Science, Department of Physics.
    Pettersson, Lars G. M.
    Stockholm University, Faculty of Science, Department of Physics.
    X-ray absorption spectroscopy and X-ray Raman scattering of water and ice; an experimental view2010In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 177, no 03-feb, p. 99-129Article in journal (Refereed)
    Abstract [en]

    Here we present a review of X-ray absorption spectroscopy and X-ray Raman scattering with the perspective to understand the spectra of water including changes with temperature, mass of the water molecule and presence of monovalent ions. The different detection schemes are discussed and it is concluded that transmission X-ray absorption measurements, using a small area where the thickness is uniform, and X-ray Raman scattering give the most reliable spectra. Different model systems are discussed such as the surface and bulk of ice and various adsorbed monolayer structures on metal surfaces.

  • 5.
    Nilsson, Anders
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Nordlund, Dennis
    Stanford.
    Waluyo, Ira
    Stanford.
    Huang, Ningdong
    Stanford.
    Ogasawara, Hirohito
    Stanford.
    Kaya, Sarp
    Stanford.
    Bergmann, Uwe
    Stanford.
    Näslund, Lars-Åke
    Stanford.
    Öström, Henrik
    Stockholm University, Faculty of Science, Department of Physics.
    Wernet, Philippe
    Helmholtz-Zentrum Berlin, Germany.
    Andersson, Klas J.
    Haldor-Topsoe.
    Schiros, Theanne
    Stockholm University, Faculty of Science, Department of Physics.
    Pettersson, Lars G.M.
    Stockholm University, Faculty of Science, Department of Physics.
    X-ray Absorption Spectroscopy and X-ray Raman Scattering of Water : an Experimental View2010In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 177, p. 99-129Article in journal (Refereed)
    Abstract [en]

    Here we present a review of X-ray absorption spectroscopy and X-ray Raman scattering with the perspective to understand the spectra of water including changes with temperature, mass of the water molecule and presence of monovalent ions. The different detection schemes are discussed and it is concluded that transmission X-ray absorption measurements, using a small area where the thickness is uniform, and X-ray Raman scattering give the most reliable spectra. Different model systems are discussed such as the surface and bulk of ice and various adsorbed monolayer structures on metal surfaces

  • 6.
    Nilsson, Anders
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Tokushima, Takashi
    Horikawa, Yuka
    Harada, Yoshihisa
    Ljungberg, Mathias P.
    Stockholm University, Faculty of Science, Department of Physics.
    Shin, Shik
    Pettersson, Lars G. M.
    Stockholm University, Faculty of Science, Department of Physics.
    Resonant inelastic X-ray scattering of liquid water2013In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 188, p. 84-100Article in journal (Refereed)
    Abstract [en]

    We review recent studies using resonant inelastic X-ray scattering (RIXS) or also here denoted X-ray emission spectroscopy (XES) on liquid water and the assignment of the two sharp peaks in the lone-pair region. Using the excitation energy dependence we connect the two peaks to specific features in the Xray absorption (XAS) spectrum which have independently been assigned to molecules in tetrahedral or distorted configurations. The polarization dependence shows that both peaks are of 1b(1) origin supporting an interpretation in terms of two structural species, tetrahedral or disordered, which is furthermore consistent with the temperature-dependence of the two peaks. We discuss effects of life-time vibrational interference and how this affects the two components differently and also leads to differences in the relative peak heights for H2O and D2O. We show furthermore that the inherent structure in molecular dynamics simulations contain the structural bimodality suggested by XES, but this is smeared out in the real structure when temperature is included. We present a discussion around alternative interpretations suggesting that the origin of the two peaks is related to ultrafast dissociation and show evidence that such a model is inconsistent with several experimental observations and theoretical concepts. We conclude that the peaks reflect a temperature-dependent balance in fluctuations between tetrahedral and disordered structures in the liquid. This is well-aligned with theories of water under supercooled conditions and higher pressures where water might exist as high- or low-density liquid with different possibilities for a transition between them. With the present work we provide a link between established models for supercooled water, where water's anomalies become extreme, and ambient water, where the anomalous contributions are weaker but still important.

  • 7.
    Schiros, Theanne
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Andersson, Klas J.
    Technical University of Denmark.
    Pettersson, Lars G.M.
    Stockholm University, Faculty of Science, Department of Physics.
    Nilsson, Anders
    Stockholm University, Faculty of Science, Department of Physics.
    Ogasawara, Hirohito
    Stanford.
    Chemical bonding of water to metal surfaces studied with core-level spectroscopies2010In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 177, p. 85-98Article in journal (Refereed)
    Abstract [en]

    The nature of the contact layer of water on surfaces is of relevance for many practical fields, including corrosion, electrochemistry, environmental science and heterogeneous catalysis. Here we focus on the geometric and electronic structure of the water contact layer on transition metal surfaces and the interaction between the water monolayer and the surface. By combining synchrotron radiation-based X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) techniques with density functional theory (DFT) computational methods we obtain element-specific information on the partial local density of states, local atomic structure, geometrical parameters and molecular orientation, allowing general principles for water–metal interaction to be derived.

  • 8. Tokushima, Takashi
    et al.
    Harada, Yoshihisa
    Horikawa, Yuka
    Takahashi, Osamu
    Senba, Yasunori
    Ohashi, Haruhiko
    Pettersson, Lars G. M.
    Stockholm University, Faculty of Science, Department of Physics.
    Nilsson, Anders
    Stockholm University, Faculty of Science, Department of Physics.
    Shin, Shik
    High resolution X-ray emission spectroscopy of water and its assignment based on two structural motifs2010In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 177, no 03-feb, p. 192-205Article in journal (Refereed)
    Abstract [en]

    We evaluate proposed interpretations of previous X-ray emission spectroscopy (XES) data on liquid water. The split peak in the lone-pair orbital region has been interpreted in terms of either two different structural motifs, tetrahedral and distorted, or as due to core-hole-induced dissociative dynamics; here we add new data on a 1:1 H2O/D2O isotopic mixture and additional spectrum simulations including the core-hole-induced dynamics. The XES spectrum of HDO is quite nicely reproduced as the sum of spectra of H2O and D2O, which we interpret as that core-hole-induced dynamics contribute only to the peak shape and do not affect the intensity ratio between tetrahedrally coordinated and distorted. We find the simulation-based interpretation of the two lone-pair peaks as being of completely different symmetries, molecular 1b(1) and dissociated 3a(1), difficult to reconcile with the experimental intensities in the 1b(2) and 3a(1) spectral regions. We report extensive theoretical simulations of spectra probing both the distance and velocity quantum distributions of the internal OH stretch; sharp features not associated with the lone-pair, that are seen when the OH stretch is treated as a classical oscillator, become smeared out when the zero-point Franck-Condon profile and momentum distribution in the v=0 level of the OH stretch are taken into account. This demonstrates that neglecting zero-point motion in simulating XES spectra of water generates artificially sharp structures. XES spectra of 1 M and 4 M hydrochloric acid (HCl) and sodium hydroxide (NaOH) are reported. These spectra indicate that dissociated species most likely can be excluded as the origin of the double 1b(1) peak structure. We thus argue that the experimental observation of two distinct peaks in the lone-pair region is less likely to be explained by an unstructured continuum model of the liquid, but is easily explained within a two-component fluctuating model.

  • 9.
    Tokushima, Takashi
    et al.
    SPring-8.
    Harada, Yoshihisa
    RIKEN/SPring-8, Japan.
    Horikawa, Yuka
    RIKEN/SPring-8, Japan.
    Takahashi, Osamu
    University of Hiroshima.
    Senba, Yasunori
    JASRI/SPring-8, Japan.
    Ohashi, Haruhiko
    JASRI/SPring-8, Japan.
    Pettersson, Lars G.M.
    Stockholm University, Faculty of Science, Department of Physics.
    Nilsson, Anders
    Stockholm University, Faculty of Science, Department of Physics.
    Shin, Shik
    RIKEN/SPring-8, Japan.
    High resolution X-ray emission spectroscopy of water and its assignment based on two structural motifs2010In: Journal of Electron Spectroscopy and Related Phenomena, ISSN 0368-2048, E-ISSN 1873-2526, Vol. 177, p. 192-205Article in journal (Refereed)
    Abstract [en]

    We evaluate proposed interpretations of previous X-ray emission spectroscopy (XES) data on liquid water. The split peak in the lone-pair orbital region has been interpreted in terms of either two different structural motifs, tetrahedral and distorted, or as due to core-hole-induced dissociative dynamics; here we add new data on a 1:1 H2O/D2O isotopic mixture and additional spectrum simulations including the core-hole-induced dynamics. The XES spectrum of HDO is quite nicely reproduced as the sum of spectra of H2O and D2O, which we interpret as that core-hole-induced dynamics contribute only to the peak shape and do not affect the intensity ratio between tetrahedrally coordinated and distorted. We find the simulation-based interpretation of the two lone-pair peaks as being of completely different symmetries, molecular 1b1 and dissociated 3a1, difficult to reconcile with the experimental intensities in the 1b2 and 3a1 spectral regions. We report extensive theoretical simulations of spectra probing both the distance and velocity quantum distributions of the internal OH stretch; sharp features not associated with the lone-pair, that are seen when the OH stretch is treated as a classical oscillator, become smeared out when the zero-point Franck–Condon profile and momentum distribution in the v = 0 level of the OH stretch are taken into account. This demonstrates that neglecting zero-point motion in simulating XES spectra of water generates artificially sharp structures. XES spectra of 1 M and 4 M hydrochloric acid (HCl) and sodium hydroxide (NaOH) are reported. These spectra indicate that dissociated species most likely can be excluded as the origin of the double 1b1 peak structure. We thus argue that the experimental observation of two distinct peaks in the lone-pair region is less likely to be explained by an unstructured continuum model of the liquid, but is easily explained within a two-component fluctuating model.

1 - 9 of 9
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf