638 research outputs found
Competition between decay and dissociation of core-excited OCS studied by X-ray scattering
We show the first evidence of dissociation during resonant inelastic soft
X-ray scattering. Carbon and oxygen K-shell and sulfur L-shell resonant and
non-resonant X-ray emission spectra were measured using monochromatic
synchrotron radiation for excitation and ionization. After sulfur, L2,3 ->
{\pi}*, {\sigma}* excitation, atomic lines are observed in the emission spectra
as a consequence of competition between de-excitation and dissociation. In
contrast the carbon and oxygen spectra show weaker line shape variations and no
atomic lines. The spectra are compared to results from ab initio calculations
and the discussion of the dissociation paths is based on calculated potential
energy surfaces and atomic transition energies.Comment: 12 pages, 6 pictures, 2 tables,
http://link.aps.org/doi/10.1103/PhysRevA.59.428
Compensation profiles among private sector employees in Sweden: Differences in work-related and health-related outcomes
How experiences and perceptions of pay and pay setting relate to employees’ job performance, willingness to remain in the organization, and health has been the subject of much debate. Previous research has typically used a variable-centered approach to investigate associations between different pay-related factors and such outcomes. In contrast, we used latent profile analysis to explore combinations of compensation characteristics (pay level, perceived horizontal pay dispersion, and procedural quality, i.e., transactional leadership and procedural pay-setting justice), combining relevant theories on the subject. Based on a nationally representative sample of private sector employees in Sweden (N = 1,146), our study identified six compensation profiles. Our key findings show, first, that higher levels of pay were generally associated with better performance, lower turnover intention, better self-rated health, and lower work-related exhaustion, especially when combined with perceptions of high procedural quality. Second, in terms of perceived horizontal pay dispersion, the results indicate that pay compression may be associated with beneficial outcomes, particularly when combined with high procedural quality. Third, procedural quality was generally associated with favorable work-related and health-related outcomes, although such positive effects may be contingent upon pay level and perceived horizontal pay dispersion. In conclusion, while pay level, perceptions of horizontal pay dispersion, and procedural quality may all matter for employee outcomes, it is important to consider their combinations
Resonant X-Ray Raman Spectra of Cu dd Excitations in Sr2CuO2Cl2
We present resonant x-ray Raman scattering results on Sr2CuO2Cl2, a model compound for high-Tc
superconductors. We demonstrate that the dd excitations can be observed and show that the polarization
dependence can be used to identify the dd excitations. We find the transition from the dx²-y² ground
state to the dxy excited state at 1.35 eV and to the degenerate dxz and dyz excited states at 1.7 eV. From
analysis of the polarization dependence we conclude that the d3z²-r² orbital energy is at 1.5 eV and not
in the midinfrared (0.5 eV) as recently suggested. We use recent theoretical arguments to show that
the d3z22r2 excitation is accompanied by a local spin flip resulting in a shift upwards of 0.2 eV due to
the exchange interaction with the neighboring spins
Electronic structure investigation of CoO by means of soft X-ray scattering
The electronic structure of CoO is studied by resonant inelastic soft X-ray
scattering spectroscopy using photon energies across the Co 2p absorption
edges. The different spectral contributions from the energy-loss structures are
identified as Raman scattering due to d-d and charge-transfer excitations. For
excitation energies close to the L3 resonance, the spectral features are
dominated by quartet-quartet and quartet-doublet transitions of the 3d7
configuration. At excitation energies corresponding to the satellites in the Co
2p X-ray absorption spectrum of CoO, the emission features are instead
dominated by charge-transfer transitions to the 3d8L-1 final state. The spectra
are interpreted and discussed with the support of simulations within the single
impurity Anderson model with full multiplet effects which are found to yield
consistent spectral functions to the experimental data.Comment: 8 pages, 2 figures, 2 tables,
http://link.aps.org/doi/10.1103/PhysRevB.65.20510
Doping Dependent Changes in Nitrogen 2 States in the Diluted Magnetic Semiconductor GaCrN
We study the electronic structure of the recently discovered diluted magnetic
semiconductor GaCrN ( = 0.01-0.10). A systematic study of the
changes in the and ligand (N) partial density of states
(DOS) of the host lattice is carried out using N 1 soft x-ray emission and
absorption spectroscopy, respectively. X-ray absorption measurements confirm
the wurtzite N 2 DOS and substitutional doping of Cr into Ga-sites. Coupled
changes in the and N 2 character DOS of
GaCrN identify states responsible for ferromagnetism consistent
with band structure calculations.Comment: 5 pages, 4 figures, submitted to Phys. Rev.
Theoretical Limb Darkening for Classical Cepheids: II. Corrections for the Geometric Baade-Wesselink Method
The geometric Baade-Wesselink method is one of the most promising techniques
for obtaining a better calibration of the Cepheid period-luminosity relation by
means of interferometric measurements of accurate diameters. In this paper we
present new wavelength- and phase-dependent limb darkening corrections based on
our time-dependent hydrodynamic models of the classical Cepheid zeta Gem. We
show that a model simulation of a Cepheid atmosphere, taking into account the
hydrodynamic effects associated with the pulsation, shows strong departures
from the limb darkening otherwise predicted by a static model. For most of its
pulsational cycle the hydrodynamic model predicts a larger limb darkening then
the equivalent static model. The hydrodynamics affects the limb darkening
mainly at UV and optical wavelengths. Most of these effects evolve slowly as
the star pulsates, but there are phases, associated with shocks propagating
into the photosphere, in which significant changes in the limb darkening take
place on time-scales of the order of less than a day. We assess the implication
of our model LD corrections fitting the geometric Baade-Wesselink distance of
zeta Gem for the available near-IR PTI data. We discuss the effects of our
model limb darkening on the best fit result, and analyze the requirements
needed to test the time-dependence of the limb darkening with future
interferometric measurements.Comment: 22 pages, 5 figures, to be published on the Astrophysical Journal,
June 1 2003 issu
Resonant inelastic soft-x-ray scattering spectra at the N1s and C1s edges of poly(pyridine-2,5-diyl)
Resonant inelastic scattering measurements of poly(pyridine-2,5-diyl) have
been performed at the N1s and C1s edges using synchrotron radiation. For
comparison, molecular orbital calculations of the spectra have been carried out
with the repeat unit as a model molecule of the polymer chain. The resonant
emission spectra show depletion of the p electron bands which is consistent
with symmetry selection and momentum conservation rules. The depletion is most
obvious in the resonant inelastic scattering spectra of carbon while the
nitrogen spectra are dominated by lone pair n orbital emission of s symmetry
and are less excitation energy dependent. By comparing the measurements to
calculations an isomeric dependence of the resonant spectra is found giving
preference to two of the four possible isomers in the polymer.Comment: 6 pages, 3 figures,
http://www.sciencedirect.com/science/article/pii/S036820489800354
Resonant soft X-ray Raman scattering of NiO
Resonant soft X-ray Raman scattering measurements on NiO have been made at
photon energies across the Ni 2p absorption edges. The details of the spectral
features are identified as Raman scattering due to d-d and charge-transfer
excitations. The spectra are interpreted within the single impurity Anderson
model, including multiplets, crystal-field and charge-transfer effects. At
threshold excitation, the spectral features consists of triplet-triplet and
triplet-singlet transitions of the 3d8 configuration. For excitation energies
corresponding to the charge-transfer region in the Ni 2p X-ray absorption
spectrum of NiO, the emission spectra are instead dominated by charge-transfer
transitions to the 3d9L-1 final state. Comparisons of the final states with
other spectroscopical techniques are also made.Comment: 9 pages, 2 figures, 2 tables,
http://iopscience.iop.org/0953-8984/14/13/32
Electronic structure investigation of CeB6 by means of soft X-ray scattering
The electronic structure of the heavy fermion compound CeB6 is probed by
resonant inelastic soft X-ray scattering using photon energies across the Ce 3d
and 4d absorption edges. The hybridization between the localized 4f orbitals
and the delocalized valence-band states is studied by identifying the different
spectral contributions from inelastic Raman scattering and normal fluorescence.
Pronounced energy-loss structures are observed below the elastic peak at both
the 3d and 4d thresholds. The origin and character of the inelastic scattering
structures are discussed in terms of charge-transfer excitations in connection
to the dipole allowed transitions with 4f character. Calculations within the
single impurity Anderson model with full multiplet effects are found to yield
consistent spectral functions to the experimental data.Comment: 9 pages, 4 figures, 1 table,
http://link.aps.org/doi/10.1103/PhysRevB.63.07510
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