Ulrik Gelius | Uppsala University (original) (raw)
Papers by Ulrik Gelius
Nachrichten aus der Chemie, 2000
Surface and Interface Analysis, 1998
Calibration of the binding energy scale in x-ray photoelectron spectroscopy (XPS) requires locati... more Calibration of the binding energy scale in x-ray photoelectron spectroscopy (XPS) requires location of the zero point. This zero point has previously been identified with the inflection point in the Fermi-edge region of a valence-band photoemission spectrum of nickel. Comparison of photoemission spectra of nickel and silver measured with monochromated x-rays shows that the inflection points near the Fermi edge differ by 45±5 meV (where the stated uncertainty indicates the standard uncertainty) at an instrumental energy resolution of 0.30 eV. This difference is due to differences in the valence-band densities of states (DOS) of the two metals. Simulations of the Ni photoemission spectrum have been performed based on the DOS calculated by Eckhardt and Fritsche, and the simulated spectrum agrees well with the measured spectrum in the near-edge region. Additional simulations of the Ni photoemission spectrum have been carried out with both monochromated Al x-rays and unmonochromated Mg and Al characteristic x-rays to determine how the Ni near-edge inflection point varies with the energy resolution of the electron energy analyzer in XPS. © 1998 John Wiley & Sons, Ltd.
Chemischer Informationsdienst, 1972
www-ssrl.slac.stanford.edu
The famous 17 th-century Swedish warship Vasa has been on display in the Vasa Museum since 1990 (... more The famous 17 th-century Swedish warship Vasa has been on display in the Vasa Museum since 1990 (Figure 1). The Vasa sank on its maiden voyage in 1628, and was recovered in 1961 after 333 years in the cold brackish water of Stockholm harbor. After extensive conservation treatment, the oaken Vasa appeared in good condition (1). However, high acidity and a rapid spread of sulfate salts and elemental sulfur were recently observed on many wooden surfaces. A research team led by Prof. Magnus Sandström, University of Stockholm, has approached the problem by using X-ray absorption near edge spectroscopy (XANES) at the sulfur Kedge. The data were recorded on SSRL's Beam Line 6-2 (2)-for the first time on wooden core samples-to speciate the sulfur compounds (3,4). The XANES spectra, measured on samples extracted at various depth of the cores, unexpectedly revealed large amounts of embedded elemental sulfur (0.2-4 mass%) in the wood, also sulfate and, in minor amounts, several sulfur compounds of intermediate oxidation states (Figure 2). X-ray photoelectron spectroscopy (XPS; 5) was in addition used to quantify all elements at the same depths (cf. Figure 2,3). The study shows that in humid museum atmospheres a stepwise sulfur oxidation produces sulfuric acid:
Surface and Interface Analysis, 1991
ABSTRACT
Physica Scripta, 1983
An Improved Model for Post-Collision Interaction (PCI) and High Resolution Ar LMM Auger Spectra R... more An Improved Model for Post-Collision Interaction (PCI) and High Resolution Ar LMM Auger Spectra Revealing New PCI Effects ... Vol. 27,245-253, 1983 An Improved Model for Post-Collision Interaction (PCI) and High Resolution Ar LMM Auger Spectra Revealing New PCI Effects ...
Physica Scripta, 1991
The high resolution X-ray excited (hν= 1487 eV) valence photoelectron spectra of N 2 and CO are p... more The high resolution X-ray excited (hν= 1487 eV) valence photoelectron spectra of N 2 and CO are presented. The spectra show a rich line structure down to 65 eV binding energy due to electron correlation effects. Several new structures are observed and new assignments ...
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 1994
The valence-band structure of pyromellitic dianhydride-4,4'-oxydianiline (PMDA-ODA) film was inve... more The valence-band structure of pyromellitic dianhydride-4,4'-oxydianiline (PMDA-ODA) film was investigated experimentally and theoretically. High-resolution valence band spectra were obtained with an x-ray photoelectron spectroscopy (XPS) instrument equipped with a monochromatic high-power Al Ka x-ray source. Several new valence-band structures were observed. Electron energy loss spectra showed the presence of an inelastic peak at about 6.5 e V loss energy. A photoelectron background was synthesized from the electron energy loss spectrum by a convolution procedure. This background gave a good understanding of the valence band spectrum. Valence effective Hamiltonian and extended Huckel calculations were performed to study the XPS intensities of the valence-band structures. The intensities were approximated by utilizing the XPS intensity model with net atomic popUlations. The total intensities were partitioned into intensity contributions from various functional groups of the polyimide. Three energetically separated regions with dominating contributions from the imide nitrogens, the ODA carbons, and the imide oxygens, respectively, were found.
Journal of the American Chemical Society, 1980
Journal of Electron Spectroscopy and Related Phenomena, 2004
The electron energy structure (EES) of the tetragonal intermetallic compounds TiCu, Ti 2 Cu and s... more The electron energy structure (EES) of the tetragonal intermetallic compounds TiCu, Ti 2 Cu and several alloys TiCu x Ni 1−x with tetragonal and cubic lattices have been investigated both experimentally by X-ray photoelectron spectroscopy (XPS) and theoretically in the framework of the self-consistent cluster version of the multiple scattering theory. The theoretical shapes of the X-ray K-emission spectra of titanium in both compounds have also been calculated and compared with experiment. A satisfactory agreement of theory and experiment was found. The character of the chemical bonding in titanium cuprides and alloys is discussed.
The Journal of Chemical Physics, 1988
ABSTRACT
Chemical Physics Letters, 1976
ESCA shifts of substituted benzene derivatives are shown to correlate with Hammett a constants. A... more ESCA shifts of substituted benzene derivatives are shown to correlate with Hammett a constants. An explanation of this correlation is given in terms of the thermodynamic model for core electron binding ener= shifts, and it is shown that ESCA shifts in benzene derivatives can be treated as a linear free energy relationship.
A high resolution ESCA spectrum of C2H2 was recorded using monochromatized AlKα excitation and wa... more A high resolution ESCA spectrum of C2H2 was recorded using monochromatized AlKα excitation and was analyzed by means of configuration interaction and multiple configuration SCF wave functions. The role of different schemes for electron-configurational selection in the initial and final states on transition moments and energies was investigated. The spectrum shows a prominent satellite structure in the inner valence region,
ICESS-9 - Proceedings of the Ninth International Conference on Electronic Spectroscopy and Struct... more ICESS-9 - Proceedings of the Ninth International Conference on Electronic Spectroscopy and Structure - Uppsala, Sweden, June 30-July 4, 2003 - Foreword
Surface and …, 2000
First results of an inter-laboratory comparison (27 participants in Europe, Japan and USA) of XPS... more First results of an inter-laboratory comparison (27 participants in Europe, Japan and USA) of XPS data obtained with non-conducting samples are presented. Binding energies of Al 2s for alumina, N 1s and imide C 1s for Kapton and Sr 3p 3=2 for a strontium titanate film on glass were obtained after static charge referencing with the help of 15 nm gold particles deposited at the surface of the test samples. For the alumina sample C 1s static charge referenced data are also presented. Repeat standard deviations (s r), between standard deviations (s b), reproducibility standard deviations (s R) and total means are evaluated from the experimental data. It can be stated that although the repeat standard deviation is as small as 0.05 eV in the best case, the standard deviation characterizing the reproducibility of the method is obviously not better than 0.15 eV in the best case at the present time. The knowledge of these standard deviations is important for metrology, validations of analytical procedures relying on qualitative photoelectron spectroscopy and XPS databanking.
Journal of Electron Spectroscopy and Related Phenomena, 1974
Abstract The different components of an ESCA-system are analyzed theoretically and conditions of ... more Abstract The different components of an ESCA-system are analyzed theoretically and conditions of optimum performance are used as basis for the design of differe
Journal of Electron …, 1973
... SPECTROSCOPY BY MEANS OF ESCA V. BORON COMPOUNDS DA ALLISON G. JOHANSSON, CJ ALLAN U. GELIUS,... more ... SPECTROSCOPY BY MEANS OF ESCA V. BORON COMPOUNDS DA ALLISON G. JOHANSSON, CJ ALLAN U. GELIUS, H. SIEGBAHN, J. ALLISON and K ... 4 K. Siegbahn, C. Nordling, A. Fahlman, R. Nordberg, K. Hamrin, J. Hedman, G. Johansson, T. Bergmark, 5.E. Karisson, I ...
Nachrichten aus der Chemie, 2000
Surface and Interface Analysis, 1998
Calibration of the binding energy scale in x-ray photoelectron spectroscopy (XPS) requires locati... more Calibration of the binding energy scale in x-ray photoelectron spectroscopy (XPS) requires location of the zero point. This zero point has previously been identified with the inflection point in the Fermi-edge region of a valence-band photoemission spectrum of nickel. Comparison of photoemission spectra of nickel and silver measured with monochromated x-rays shows that the inflection points near the Fermi edge differ by 45±5 meV (where the stated uncertainty indicates the standard uncertainty) at an instrumental energy resolution of 0.30 eV. This difference is due to differences in the valence-band densities of states (DOS) of the two metals. Simulations of the Ni photoemission spectrum have been performed based on the DOS calculated by Eckhardt and Fritsche, and the simulated spectrum agrees well with the measured spectrum in the near-edge region. Additional simulations of the Ni photoemission spectrum have been carried out with both monochromated Al x-rays and unmonochromated Mg and Al characteristic x-rays to determine how the Ni near-edge inflection point varies with the energy resolution of the electron energy analyzer in XPS. © 1998 John Wiley & Sons, Ltd.
Chemischer Informationsdienst, 1972
www-ssrl.slac.stanford.edu
The famous 17 th-century Swedish warship Vasa has been on display in the Vasa Museum since 1990 (... more The famous 17 th-century Swedish warship Vasa has been on display in the Vasa Museum since 1990 (Figure 1). The Vasa sank on its maiden voyage in 1628, and was recovered in 1961 after 333 years in the cold brackish water of Stockholm harbor. After extensive conservation treatment, the oaken Vasa appeared in good condition (1). However, high acidity and a rapid spread of sulfate salts and elemental sulfur were recently observed on many wooden surfaces. A research team led by Prof. Magnus Sandström, University of Stockholm, has approached the problem by using X-ray absorption near edge spectroscopy (XANES) at the sulfur Kedge. The data were recorded on SSRL's Beam Line 6-2 (2)-for the first time on wooden core samples-to speciate the sulfur compounds (3,4). The XANES spectra, measured on samples extracted at various depth of the cores, unexpectedly revealed large amounts of embedded elemental sulfur (0.2-4 mass%) in the wood, also sulfate and, in minor amounts, several sulfur compounds of intermediate oxidation states (Figure 2). X-ray photoelectron spectroscopy (XPS; 5) was in addition used to quantify all elements at the same depths (cf. Figure 2,3). The study shows that in humid museum atmospheres a stepwise sulfur oxidation produces sulfuric acid:
Surface and Interface Analysis, 1991
ABSTRACT
Physica Scripta, 1983
An Improved Model for Post-Collision Interaction (PCI) and High Resolution Ar LMM Auger Spectra R... more An Improved Model for Post-Collision Interaction (PCI) and High Resolution Ar LMM Auger Spectra Revealing New PCI Effects ... Vol. 27,245-253, 1983 An Improved Model for Post-Collision Interaction (PCI) and High Resolution Ar LMM Auger Spectra Revealing New PCI Effects ...
Physica Scripta, 1991
The high resolution X-ray excited (hν= 1487 eV) valence photoelectron spectra of N 2 and CO are p... more The high resolution X-ray excited (hν= 1487 eV) valence photoelectron spectra of N 2 and CO are presented. The spectra show a rich line structure down to 65 eV binding energy due to electron correlation effects. Several new structures are observed and new assignments ...
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 1994
The valence-band structure of pyromellitic dianhydride-4,4'-oxydianiline (PMDA-ODA) film was inve... more The valence-band structure of pyromellitic dianhydride-4,4'-oxydianiline (PMDA-ODA) film was investigated experimentally and theoretically. High-resolution valence band spectra were obtained with an x-ray photoelectron spectroscopy (XPS) instrument equipped with a monochromatic high-power Al Ka x-ray source. Several new valence-band structures were observed. Electron energy loss spectra showed the presence of an inelastic peak at about 6.5 e V loss energy. A photoelectron background was synthesized from the electron energy loss spectrum by a convolution procedure. This background gave a good understanding of the valence band spectrum. Valence effective Hamiltonian and extended Huckel calculations were performed to study the XPS intensities of the valence-band structures. The intensities were approximated by utilizing the XPS intensity model with net atomic popUlations. The total intensities were partitioned into intensity contributions from various functional groups of the polyimide. Three energetically separated regions with dominating contributions from the imide nitrogens, the ODA carbons, and the imide oxygens, respectively, were found.
Journal of the American Chemical Society, 1980
Journal of Electron Spectroscopy and Related Phenomena, 2004
The electron energy structure (EES) of the tetragonal intermetallic compounds TiCu, Ti 2 Cu and s... more The electron energy structure (EES) of the tetragonal intermetallic compounds TiCu, Ti 2 Cu and several alloys TiCu x Ni 1−x with tetragonal and cubic lattices have been investigated both experimentally by X-ray photoelectron spectroscopy (XPS) and theoretically in the framework of the self-consistent cluster version of the multiple scattering theory. The theoretical shapes of the X-ray K-emission spectra of titanium in both compounds have also been calculated and compared with experiment. A satisfactory agreement of theory and experiment was found. The character of the chemical bonding in titanium cuprides and alloys is discussed.
The Journal of Chemical Physics, 1988
ABSTRACT
Chemical Physics Letters, 1976
ESCA shifts of substituted benzene derivatives are shown to correlate with Hammett a constants. A... more ESCA shifts of substituted benzene derivatives are shown to correlate with Hammett a constants. An explanation of this correlation is given in terms of the thermodynamic model for core electron binding ener= shifts, and it is shown that ESCA shifts in benzene derivatives can be treated as a linear free energy relationship.
A high resolution ESCA spectrum of C2H2 was recorded using monochromatized AlKα excitation and wa... more A high resolution ESCA spectrum of C2H2 was recorded using monochromatized AlKα excitation and was analyzed by means of configuration interaction and multiple configuration SCF wave functions. The role of different schemes for electron-configurational selection in the initial and final states on transition moments and energies was investigated. The spectrum shows a prominent satellite structure in the inner valence region,
ICESS-9 - Proceedings of the Ninth International Conference on Electronic Spectroscopy and Struct... more ICESS-9 - Proceedings of the Ninth International Conference on Electronic Spectroscopy and Structure - Uppsala, Sweden, June 30-July 4, 2003 - Foreword
Surface and …, 2000
First results of an inter-laboratory comparison (27 participants in Europe, Japan and USA) of XPS... more First results of an inter-laboratory comparison (27 participants in Europe, Japan and USA) of XPS data obtained with non-conducting samples are presented. Binding energies of Al 2s for alumina, N 1s and imide C 1s for Kapton and Sr 3p 3=2 for a strontium titanate film on glass were obtained after static charge referencing with the help of 15 nm gold particles deposited at the surface of the test samples. For the alumina sample C 1s static charge referenced data are also presented. Repeat standard deviations (s r), between standard deviations (s b), reproducibility standard deviations (s R) and total means are evaluated from the experimental data. It can be stated that although the repeat standard deviation is as small as 0.05 eV in the best case, the standard deviation characterizing the reproducibility of the method is obviously not better than 0.15 eV in the best case at the present time. The knowledge of these standard deviations is important for metrology, validations of analytical procedures relying on qualitative photoelectron spectroscopy and XPS databanking.
Journal of Electron Spectroscopy and Related Phenomena, 1974
Abstract The different components of an ESCA-system are analyzed theoretically and conditions of ... more Abstract The different components of an ESCA-system are analyzed theoretically and conditions of optimum performance are used as basis for the design of differe
Journal of Electron …, 1973
... SPECTROSCOPY BY MEANS OF ESCA V. BORON COMPOUNDS DA ALLISON G. JOHANSSON, CJ ALLAN U. GELIUS,... more ... SPECTROSCOPY BY MEANS OF ESCA V. BORON COMPOUNDS DA ALLISON G. JOHANSSON, CJ ALLAN U. GELIUS, H. SIEGBAHN, J. ALLISON and K ... 4 K. Siegbahn, C. Nordling, A. Fahlman, R. Nordberg, K. Hamrin, J. Hedman, G. Johansson, T. Bergmark, 5.E. Karisson, I ...