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1.
Braicovich L Ghiringhelli G Tagliaferri A van der Laan G Annese E Brookes NB 《Physical review letters》2005,95(26):267402
We present measurements of the magnetic circular dichroism in x-ray resonant emission in the perpendicular geometry (circularly polarized x rays at normal incidence to the magnetization) for L(2,3) the absorption region in Fe, Co, and Ni metal. The results show that spin-dependent screening of the core hole takes place within the scattering time scale, which is supported by the absence of the effect in ionic systems. This allows an assessment of the time scale for the screening process (up to a few femtoseconds). The process is almost complete within the scattering time for Fe and Co, but this is not the case for the narrow band metal Ni which shows a much slower dynamics. 相似文献
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F. Cerrina I. Abbati L. Braicovich F. Levy G. Margaritondo 《Solid State Communications》1978,26(2):99-102
UV photoemission spectroscopy (UPS) experiments have been carried out on the layer compound ZnIn2S4 employing several different photon energies in the range . The energy distribution curves (EDC's) exhibit four valence band density of states structures besides the Zn 3d peak. These five peaks appear 0.90 eV, 1.6 eV, 4.3 eV, 5.8 eV and 8.7 eV respectively below the top of the valence band, Ev. The atomic orbital character of the shallowest peak A appears different from that of the three deeper valence band peaks B, C and D and this is discussed in terms of the more or less pronounced ionic character of the intralayer chemical bonds. These results demonstrate that an overall understanding of the electronic states in complex structures can be achieved by an approach based on photoemission experiments and chemical bonding considerations which has been widely used in the past to study simple binary layer compounds. 相似文献
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K. Kummer A. Tamborrino A. Amorese M. Minola L. Braicovich N. B. Brookes G. Ghiringhelli 《Journal of synchrotron radiation》2017,24(2):531-536
A software with a graphical user interface has been developed with the aim of facilitating the data analysis for users of a new resonant inelastic X‐ray scattering (RIXS) spectrometer installed at the ESRF beamline ID32. The software is organized in modules covering all relevant steps in the data reduction from a stack of several hundred two‐dimensional CCD images to a single RIXS spectrum. It utilizes both full charge integration and single‐photon centroiding to cope with high‐flux and high‐resolution requirements. Additional modules for further data analysis and the extraction of instrumental parameters are available. The software has been in routine use for about a year now and in that time many additional features have been incorporated. It now meets the users' need for an easy‐to‐use data analysis tool that allows looking at and understanding data as it is acquired and thus steering users' experiments more efficiently. 相似文献
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G. Ghiringhelli A. Piazzalunga X. Wang A. Bendounan H. Berger F. Bottegoni N. Christensen C. Dallera M. Grioni J.-C. Grivel M. Moretti Sala L. Patthey J. Schlappa T. Schmitt V. Strocov L. Braicovich 《The European physical journal. Special topics》2009,169(1):199-205
Resonant inelastic x-ray scattering in the soft x-ray
regime has been profiting much from technical advances that have
lowered considerably the instru- mental linewidth. At the ADRESS beam
line of the Swiss Light Source the SAXES spectrometer can be used to
measure RIXS spectra at the L edges of the 3d transition metals
with unprecedented energy resolution, of the order of 100 meV for
Mn, Ni and Cu. We present here some preliminary spectra on CuO,
malachite, NiO, NiCl2, MnO and LaMnO3. The dd excitations
are very well resolved allowing accurate experimental evaluation of
3d state energy splitting. The low energy scale becomes
accessible opening the way to the study of collective excitations in
strongly correlated electron systems, like magnons and orbitons. 相似文献
5.
D. D. Sarma F. U. Hillebrecht M. Campagna C. Carbone J. Nogami I. Lindau T. W. Barbee L. Braicovich I. Abbati B. De Michelis 《Zeitschrift für Physik B Condensed Matter》1985,59(2):159-165
We present X-ray absorption spectra (XAS) obtained with synchrotron radiaton at the PdL
2,3 edges of Pd–Al alloys and Bremsstrahlung Isochromat Spectra (BIS) at 1,486.7 eV of Pd–Al alloys and of Pd2Si. The XAS and BIS results for the alloys are very similar indicating that the effect of the core potential (e.g. many-body, electronhole excitation) is negligible. The BIS results on Pd2Si show differences with respect to Pd–Al due to the more localized bonds. The comparison between XAS and BIS data in Pd2Si is still an open problem and might indicate a more subtle role of the core-hole potential. 相似文献
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Braicovich L Tagliaferri A van der Laan G Ghiringhelli G Brookes NB 《Physical review letters》2003,90(11):117401
We present an approach to x-ray resonant Raman scattering suitable for sum-rule analysis. In magnetic systems it gives ground state information as represented by an expansion in coupled multipoles of orbital and spin moments. The experiment is based on the angular dependence of the integrated peak intensities. In 3d transition elements one obtains information up to order 4 from the channel 2p(6)3d(n)-->2p(5)3d(n+1)-->2p(6)3s(1)3d(n+1). By combining these results with L(2,3) absorption dichroism, we show quantitatively the atomiclike properties of cobalt in CoFe2O4 up to high-order multipoles. 相似文献