Experimental evidence of thermal fluctuations on the x-ray absorption near-edge structure at the aluminum<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>K</mml:mi></mml:math>edge

Manuel, D. V.; Cabaret, Delphine; Brouder, Christian; Sainctavit, Philippe; Bordage, Amélie; Trcera, Nicolas

doi:10.1103/physrevb.85.224108

Cited by 47 publications

(44 citation statements)

References 99 publications

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“…Such a contraction of the XANES features as modelled within DFT is often observed Trcera et al, 2009) and could be corrected by performing additional GW self-energy calculation using a many-pole model (Kas et al, 2007(Kas et al, , 2009). The discrepancy related to the overestimation of the peak A intensity was already observed at the Al K-edge in previous simulations using the same theoretical approach Cabaret and Brouder, 2009;Manuel et al, 2012). It was attributed to the overestimation of the attraction potential created by the 1s core-hole in the full core-hole approach.…”

Section: Al K-edge Xanes Spectra Of Aluminous Goethite and Diasporementioning

confidence: 76%

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Probing the local environment of substitutional Al $$^{3+}$$ 3 + in goethite using X-ray absorption spectroscopy and first-principles calculations

et al. 2015

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We present experimental and calculated Al K-edge X-ray absorption near-edge structure (XANES) spectra of aluminous goethite with 10 to 33 mol % of AlOOH and diaspore. Significant changes are observed experimentally in the near and pre-edge regions with increasing Al concentration in goethite. First-principles calculations based on density-functional theory (DFT) reproduce successfully the experimental trends. This permit to identify the electronic and structural parameters controlling the spectral features and to improve our knowledge of the local environment of Al 3+ in the goethite-diaspore partial solid solution.In the near-edge region, the larger peak spacing in diaspore compared to Al-bearing goethite is related to the nature (Fe or Al) of the first cation neighbours around the absorbing Al atom (Al*). The intensity ratio of the two near-edge peaks, which decreases with Al concentration, is correlated with the average distance of the first cations around Al* and the distortion of the AlO 6 octahedron. Finally, the decrease in intensity of the pre-edge features with increasing Al concentration is due to the smaller number of Fe atoms in the local environment of Al since Al atoms tend to cluster. In addition, it is found that the pre-edge features of the Al K-edge XANES spectra enable to probe indirectly empty 3d states of Fe. Energetic, structural and spectroscopic results suggest that for Al concentrations around 10 mol %, Al atoms can be considered as isolated whereas above 25 mol %, Al clusters are more likely to occur.

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Section: Al K-edge Xanes Spectra Of Aluminous Goethite and Diasporementioning

confidence: 76%

“…To avoid as much as possible self-absorption, the detection angle is set at nearly 0 • during all the measurements. The data are normalised and corrected for self-absorption, as described by Manuel et al (2012). A step of 0.05 eV is used to acquire the spectra in the region 1560-1580 eV.…”

Section: Samples and Experimental Al Kedge Xanesmentioning

confidence: 99%

Probing the local environment of substitutional Al $$^{3+}$$ 3 + in goethite using X-ray absorption spectroscopy and first-principles calculations

et al. 2015

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“…Recent experimental results by Mannel et al [6], however, show the pre-edge shift toward lower energy for higher temperature, which suggests the finite contribution from the second term of eqs. (2.60) and (2.61).…”

Section: Franck-condon Factormentioning

confidence: 87%

“…Prominent temperature dependence of the pre-edge structures are observed in Ti K-edge XANES in SrTiO 3 from 15 to 300K: One of the pre-edge peaks shows an increase of the intensity with temperature as observed by Nozawa et al [5]. More recently Manuel et al present the Al K-edge XANES spectra of corundum and beryl for temperature range from 300 to 930 K [6]. These experimental results provide an evidence of the role of thermal fluctuation in XANES at the Al K edge: The pre-edge grows and shifts to lower energy with temperature.…”

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confidence: 86%

Phonon effects on X-ray absorption and X-ray photoemission spectra

Fujikawa

Sakuma

Niki

et al. 2015

Journal of Electron Spectroscopy and Related Phenomena

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Some important phonon effects observed in X-ray absorption and X-ray photoemis-sion spectra are discussed on the basis of nonequilibrium Green's function theory. For the pre-edge structures, the intensity associated with forbidden electric dipole transition is sensitive to temperature compared with allowed electric quadrupole transition. We also discuss the FC and their interference, which have negligible contribution to pre-edge intensity and energy shift. The quasi-particle energy is also influenced by the core displacement which can be responsible for the peak shift of the pre-edges. We also discuss the photoelectron angular distribution caused by the thermal atomic vibration. Research HighlightsPage 2 of 32 A c c e p t e d M a n u s c r i p t Phonon Effects on X-ray Absorption and X-ray Photoemission Spectra Abstract Some important phonon effects observed in X-ray absorption and X-ray photoemission spectra are discussed on the basis of nonequilibrium Green's function theory. This theoretical framework allows us to incorporate phonon effects, such as DebyeWaller (DW) factors, Franck-Condon (FC) factors and electron-phonon interactions in a natural way. In the case of core level excitations, we can take into account the core-hole effects in lesser Green's function g < and photoelectron propagation in greater Green's function g > . For the core-hole propagation we derive some formulas to describe the thermally displaced core functions: we have p components even for deep core s orbital due to the thermal motion. We should notice that the thermal fluctuation is quite small but it is already in the order of the spread of the core functions. Applying Mermin's theorem, we can calculate the thermal average of the hole propagator g < : Here an important ingredient is the Debye-Waller factor used in X-ray and neutron diffraction. For the pre-edge structures, the intensity associated with forbidden electric dipole transition is sensitive to the temperature compared with allowed electric quadrupole transition. We also discuss the FC and their interference, which have negligible contribution to pre-edge intensity and energy shift. The quasi-particle energy is also influenced by the core displacement which can be responsible for the peak shift of the pre-edges. We also discuss the changes of the photoelectron angular distributions caused by the thermal atomic vibration.

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“…The normalization and the self-absorption correction of the spectra are performed by a code using the procedure described in ref. [21,22].…”

Section: Experiments and Calculation Detailsmentioning

confidence: 99%

Role of sulfur in BaVS3 probed by S K-edge absorption spectroscopy

Ilakovac

Boulfaat

Joly

et al. 2015

Physica B: Condensed Matter

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We show that the quasi-1D behavior of BaVS 3 can be understood analyzing the X-ray absorption near edge spectra at the sulfur K edge. Linear dichroïsm experiments, analyzed with the help of ab initio calculations, reveal two strong and polarization dependent pre-edge features, induced by the band character of the 3d vanadium levels. They are related to crystal field split t 2g and e g states. When the temperature is lowered, the t 2g feature shifts progressively to higher energy, and its intensity increases for the polarization along the c-axis, stacking direction of the V-S face sharing octahedra. This behavior points to the depletion of sulfur states and thus the lack of S 3p -V 3d hybridization in the direction of V-S chains.

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Experimental evidence of thermal fluctuations on the x-ray absorption near-edge structure at the aluminumKedge

Cited by 47 publications

References 99 publications

Probing the local environment of substitutional Al $$^{3+}$$ 3 + in goethite using X-ray absorption spectroscopy and first-principles calculations

Probing the local environment of substitutional Al $$^{3+}$$ 3 + in goethite using X-ray absorption spectroscopy and first-principles calculations

Phonon effects on X-ray absorption and X-ray photoemission spectra

Role of sulfur in BaVS3 probed by S K-edge absorption spectroscopy

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