Search

X-ray scattering spectra of Cu and Ni metals have been measured using monochromatic synchrotron radiation tuned from far above to more than 10 eV below threshold. Energy conservation in the scattering process is found to be sufficient to explain the modulation of the spectral shape, neglecting momentum conservation and channel interference. At excitation energies close to and above threshold, the emission spectra map the occupied local partial density of states. For the subthreshold excitations, the high-energy flank of the inelastic scattering exhibits a Raman-type linear dispersion, and an asymmetric low-energy tail develops. For excitation far below threshold the emission spectra are proportional to a convolution of the occupied and unoccupied local partial densities of states.

Surface and interface properties of Cu thin films (1-4 monolayers) deposited on Ni(100) have been extracted by means of x-ray absorption spectroscopy and analyzed in combination with ab initio density-functional calculations. An unoccupied Cu surface stat

The electronic structure of C-60 and potassium doped C-60 has been studied by soft-X-ray absorption and emission spectroscopies. The C K alpha emission spectrum of doped C-60 shows a resolved filled lowest unoccupied molecular orbitals (LUMO) (t(1 alpha)), Addresses: Guo JH, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Lawrence Berkeley Natl Lab, Berkeley, CA 94720 USA.

Soft X-ray emission spectroscopy has been used as a chemical probe in the characterization of thin film materials. Some examples of soft X-ray emission studies are presented to show the chemical sensitivity, site selectivity and depth dependence of this m, Addresses: Guo JH, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. ABB Corp Res, Avd D, S-72178 Vasteras, Sweden. ITE, S-83125 Ostersund, Sweden.

The electronic structure of YBa2CU3O6.02, YBa2Cu3O6.94 and YBa2Cu4O8 has been studied by using soft-xray absorption and emission spectroscopies. The unoccupied and occupied states are reflected by O 1s is absorption and O K alpha emission spectra. An abso, Addresses: Guo JH, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Chalmers Univ Technol, Dept Inorgan Chem, S-41296 Gothenburg, Sweden. Univ Gothenburg, S-41296 Gothenburg, Sweden.

Understanding of the reactivity of bio-organic molecules and their interaction with metal surfaces is of fundamental importance. Using the simplest amino acid, glycine, chemisorbed on Cu(110) and the related model adsorbates formate, acetate, and ammonia, Addresses: Nilsson A, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Univ Stockholm, FYSIKUM, S-11385 Stockholm, Sweden.

The application of resonant inelastic x-ray scattering and resonantly excited x-ray emission to adsorbates has evolved into a powerful technique to investigate the valence electronic structure of adsorbates in an atom-specific and orbital-symmetry-selecti, Addresses: Fohlisch A, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Univ Stockholm, FYSIKUM, S-11385 Stockholm, Sweden.

We present a study of the bonding of formate (HCOO) and acetate (CH3COO) chemisorbed on Cu(110) using core level spectroscopies in combination with theoretical calculations. For the first time, we apply x-ray emission spectroscopy (XES) to these systems., Addresses: Karis O, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Univ Stockholm, FYSIKUM, S-11385 Stockholm, Sweden. IBM Corp, Almaden Res Ctr, Div Res, San Jose, CA 95120 USA.

Orbital-resolved O K alpha x-ray fluorescence spectra ofin-CuO2-plane [O(1)] and epical [O(2)] oxygen atoms were obtained for La1.9Sr0.1CuO4 by making an appropriate choice of the energy of incident photons and the crystal orientation relative to the pola, Addresses: Butorin SM, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden.

The study of high-T-c superconductors and related compounds by means of soft X-ray fluorescence spectroscopy with monochromatic photon excitation is reviewed. It is shown that this spectroscopy provides a powerful tool for probing the local electronic str, Addresses: Butorin SM, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden.

We present a combined density functional theory and x-ray emission spectroscopy study of the bonding and chemistry of glycine (NH2CH2COOH) chemisorbed on Cu(110). The amino acid deprotonates upon adsorption. The adsorbate exhibits a rich surface chemistry, Addresses: Pettersson LGM, Univ Stockholm, Dept Phys, Box 6730, S-11385 Stockholm, Sweden. Univ Stockholm, Dept Phys, S-11385 Stockholm, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden.

The electronic structure of a Cu monolayer buried in Ni fcc(100) is studied by means of x-ray emission and absorption spectroscopies in combination with first principles calculations. The local character of the x-ray probes allows us to investigate change, Addresses: Karis O, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Univ Paris 06, Chim Phys Lab, F-75231 Paris, France. Univ Uppsala, Condensed Matter Theory Grp, S-75121 Uppsala, Sweden. Univ

The electronic structure of a Cu monolayer buried in Ni fcc(100) is studied by means of x-ray emission and absorption spectroscopies in combination with first principles calculations. The local character of the x-ray probes allows us to investigate changes in the chemical interaction for these ultrathin film systems. In comparison to bulk Cu, the occupied d states of a buried Cu monolayer, as mapped in the x-ray emission spectrum, remain mostly unaltered. The absorption spectrum on the other hand shows that the empty states of the buried Cu monolayer are modified, and instead resemble the unoccupied electronic density of bulk Ni. These findings agree well with our first principle electronic structure calculations and the results are interpreted in terms of short- and long-range hybridization., Original Publication:O. Karis, Martin Magnuson, T Wiell, M. Weinelt, N. Wassdahl, A. Nilsson, N. Mårtensson, E. Holmström, A. M. N. Niklasson and Olle Eriksson, Observation of short- and long-range hybridization of a buried Cu monolayer in Ni, 2000, Physical Review B Condensed Matter, (62), 24, R16239-R16242.http://dx.doi.org/10.1103/PhysRevB.62.R16239Copyright: American Physical Society http://www.aps.org

We present a study of a monolayer of ammonia (NH3) adsorbed on Cu(110) using core level spectroscopies in combination with ab initio calculations based on density functional theory. In particular, x-ray emission spectroscopy has been applied, providing an, Addresses: Hasselstrom J, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Univ Stockholm, FYSIKUM, S-11385 Stockholm, Sweden. IBM Corp, Almaden Res Ctr, Div Res, San Jose, CA 95120 USA.

The new undulator beamline I511 at MAX-lab, now under commissioning, has been optimized for X-ray emission and photoelectron spectroscopies. Using an SX-700 high flux monochromator the accessible photon energy range is from 90 eV to about 1500 eV. The per, Addresses: Denecke R, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Univ Lund, Max Lab, S-22100 Lund, Sweden.

Vibrational fine structure has been observed in the Cls and O1s photoelectron lines of CO adsorbed on Ni(100). This allows a detailed separation of vibrational and electronic contributions to the line profile. The main line is found to represent the fully, Addresses: Fohlisch A, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Tech Univ Munich, Dept Phys E20, D-85747 Garching, Germany.

Both the occupied and unoccupied adsorbate valence states have been probed by x-ray emission and x-ray absorption spectroscopies for N/Cu(100) and the low coverage phase of O/Cu(100). By carrying out experiments using two different measurement geometries, Addresses: Wiell T, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Univ Calif Lawrence Livermore Natl Lab, Livermore, CA 94551 USA.

The molecular orientation of an ordered monolayer of glycine adsorbed on Cu(110) has been studied using X-ray Photoelectron Spectroscopy (XPS), Near Edge X-ray Absorption Fine Structure (NEXAFS), X-ray Photoelectron Diffraction (XPD), Low-Energy Electron, Addresses: Hasselstrom J, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Univ Stockholm, FYSIKUM, S-11385 Stockholm, Sweden. IBM Corp, Almaden Res Ctr, Div Res, San Jose, CA 95120 USA.

The electronic structure of the system N-2/Ni(100) has been studied by means of angle-resolved x-ray-emission spectroscopy (XES) and ab initio calculations. XES allows a symmetry-resolved decomposition of the 2p density of states projected on each N atom., Addresses: Bennich P, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Univ Stockholm, FYSIKUM, S-11385 Stockholm, Sweden. IBM Corp, Div Res, Almaden Res Ctr, San Jose, CA 95120 USA.

Experimental and theoretical investigations are made for the polarization dependence in the resonant X-ray emission spectra due to the Cu 3d --> 2p electronic transition under the Cu 2p --> 3d resonant excitation (Cu 2p-RXES) in La2CuO4. It is shown that, Addresses: Duda LC, Boston Univ, Dept Phys, 590 Commonwealth Ave, Boston, MA 02215 USA. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. Univ Halle Wittenberg, Fachbereich Phys, D-06108 Halle, Germany. Univ Osaka Prefecture, Coll Integrated Arts & Sci, S

The valence electronic structure of benzene chemisorbed on Ni(100) and Cu(110) has been studied using angle-dependent x-ray emission and x-ray absorption spectroscopy. These techniques allow us to resolve the benzene p contributions involved in the chemic, Addresses: Weinelt M, Univ Uppsala, Dept Phys, Box 530, S-75121 Uppsala, Sweden. Univ Uppsala, Dept Phys, S-75121 Uppsala, Sweden. IBM Corp, Almaden Res Ctr, Div Res, San Jose, CA 95120 USA. Univ Erlangen Nurnberg, Lehrstuhl Festkorperphys, D-8520 Erlange

The basis for resonant photoemission is discussed in connection with data for a physisorption system, Ar/Pt(111) and a 3d transition metal, Ni(100). For Ar/Pt(111) the quasi-localized character of the intermediate state leads to two types of features in t, Addresses: Martensson N, UNIV UPPSALA, DEPT PHYS, BOX 530, S-75121 UPPSALA, SWEDEN. IBM CORP, ALMADEN RES CTR, DIV RES, SAN JOSE, CA 95120.

X-ray emission spectroscopy applied to adsorbate systems is shown to reveal new details of the chemical bond formed at surfaces. An atom and symmetry projected view of the bonding orbitals is obtained. We will present recent studies of N-2 and CO on Ni(10, Addresses: Nilsson A, UNIV UPPSALA, DEPT PHYS, BOX 530, S-75121 UPPSALA, SWEDEN. IBM CORP, ALMADEN RES CTR, DIV RES, SAN JOSE, CA 95120.

Unambiguous evidence for resonant photoemission in Ni is presented. Interference effects are identified at the 2p edges for the valence band and the 6 eV satellite. A rapid transition from a resonant Raman to an Auger-like regime shows that the core-excit, Addresses: Weinelt M, UNIV UPPSALA, DEPT PHYS, BOX 530, S-75121 UPPSALA, SWEDEN. IBM CORP, ALMADEN RES CTR, DIV RES, SAN JOSE, CA 95120.

At the BW3 beamline (HASYLAB/Hamburg) we have studied the Fe L and Cu L emission spectra of FeO, alpha-Fe2O3 and La2CuO4, respectively, using different orientations of the single crystal samples with respect to the polarization of the exciting radiation a, Addresses: Drager G, UNIV HALLE WITTENBERG, FACHBEREICH PHYS, D-06108 HALLE, GERMANY. UNIV UPPSALA, DEPT PHYS, S-75121 UPPSALA, SWEDEN.

High resolution x-ray emission spectroscopy is shown to reveal unprecedented details of the chemical bond formed between a molecule and a transition metal surface. An atom and symmetry projected view of the bonding orbitals is obtained. We find that all o, Addresses: Nilsson A, UNIV UPPSALA, DEPT PHYS, BOX 530, S-75121 UPPSALA, SWEDEN. IBM CORP, ALMADEN RES CTR, DIV RES, SAN JOSE, CA 95120.

A review is presented of some recent advancements in resonant soft X-ray fluorescence spectroscopy applied to molecules. The concept of inelastic scattering is discussed for molecules with an element of symmetry, which introduces degeneracy or near-degene, Addresses: Nordgren J, UNIV UPPSALA, DEPT PHYS, BOX 530, S-75121 UPPSALA, SWEDEN.

The results of 4f --> 3d x-ray fluorescence measurements, performed with monochromatic-photon excitation at Pr M-4,M-5 absorption edges of PrO2, are presented and discussed in the framework of an Anderson impurity model. The dependence of the fluorescence, Addresses: Butorin SM, UNIV UPPSALA, DEPT PHYS, BOX 530, S-75121 UPPSALA, SWEDEN. UNIV TOKYO, INST SOLID STATE PHYS, MINATO KU, TOKYO 106, JAPAN. LUND UNIV, MAX LAB, S-22100 LUND, SWEDEN.

The L2,3 x-ray emission of Cu metal has been measured using monochromatic synchrotron radiation. The self-absorption effect in the spectra is shown to be very small in our experimental geometry. From the quantitative analysis of spectra recorded at different excitation energies, the L3/L2 emission intensity ratio and the partial Auger width are extracted. High-energy satellite features on the L3 emission line are separated by a subtraction procedure. The satellite intensity is found to be slowly increasing for excitation energies between the L3, L2, and L1 core-level thresholds due to shake-up and shake-off transitions. As the excitation energy passes the L2 threshold, a step of rapidly increasing satellite intensity of the L3 emission is found due to additional Coster-Kronig processes., Original Publication:Martin Magnuson, N. Wassdahl and J. Nordgren, Energy dependence of Cu L2,3 satellites using synchrotron excited x-ray-emission spectroscopy, 1997, Physical Review B. Condensed Matter and Materials Physics, (56), 12238-12242.http://dx.doi.org/10.1103/PhysRevB.56.12238Copyright: American Physical Societyhttp://www.aps.org

Unambiguous evidence for resonant photoemission in Ni is presented. Interference effects are identified at the 2p edges for the valence band and the 6 eV satellite. A rapid transition from a resonant Raman to an Auger-like regime shows that the core-excited states above threshold are not localized enough to significantly enhance the photoemission intensity, implying a large fraction of incoherent intensity. The results indicate that the appearance of interference effects does not require strong localization of the intermediate state., Original Publication:M. Weinelt, A. Nilsson, Martin Magnuson, T. Wiell, N. Wassdahl, O. Karis, A. Föhlisch, N. Mårtensson, J. Stöhr and M. Samant, Resonant Photoemission at the 2p Edges of Ni: Resonant Raman and Interference Effects, 1997, Physical Review Letters, (78), 5, 967-970.http://dx.doi.org/10.1103/PhysRevLett.78.967Copyright: American Physical Societyhttp://www.aps.org

High-resolution L(3) x-ray absorption and emission spectra of Co and Cu in Co/Cu multilayers are shown to provide unique information on the occupied and unoccupied density of d states near buried interfaces. The d bands of both Co and Cu interfacial layer, Addresses: Nilsson A, UNIV UPPSALA, DEPT PHYS, BOX 530, S-75121 UPPSALA, SWEDEN. IBM CORP, ALMADEN RES CTR, DIV RES, SAN JOSE, CA 95120. TECH UNIV DENMARK, DEPT PHYS, DK-2800 LYNGBY, DENMARK.

Resonant soft x-ray emission spectroscopy has been applied to study the issue of symmetry breaking upon core-hole excitation in molecular oxygen. The results provide direct evidence that the inversion symmetry is not broken in the core-excited states. Fur, Addresses: Glans P, UNIV UPPSALA, DEPT PHYS, BOX 530, S-75121 UPPSALA, SWEDEN. LINKOPING UNIV, INST PHYS & MEASUREMENT TECHNOL, S-58183 LINKOPING, SWEDEN. UNIV OREGON, DEPT PHYS, EUGENE, OR 97403. UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 9