scholarly journals Resonant X-ray Emission Spectroscopy with a SASE Beam

2021 ◽  
Vol 11 (18) ◽  
pp. 8775
Author(s):  
Wojciech Błachucki ◽  
Yves Kayser ◽  
Anna Wach ◽  
Rafał Fanselow ◽  
Christopher Milne ◽  
...  
Keyword(s):  
Free Electron Laser ◽  
Emission Spectroscopy ◽  
Reconstruction Algorithm ◽  
High Energy ◽  
High Energy Resolution ◽  
Oxide Nanoparticles ◽  
Pulse Spectrum ◽  
X Ray ◽  
Reconstructed Data

Aqueous iron (III) oxide nanoparticles were irradiated with pure self-amplified spontaneous emission (SASE) X-ray free-electron laser (XFEL) pulses tuned to the energy around the Fe K-edge ionization threshold. For each XFEL shot, the incident X-ray pulse spectrum and Fe Kβ emission spectrum were measured synchronously with dedicated spectrometers and processed through a reconstruction algorithm allowing for the determination of Fe Kβ resonant X-ray emission spectroscopy (RXES) plane with high energy resolution. The influence of the number of X-ray shots employed in the experiment on the reconstructed data quality was evaluated, enabling the determination of thresholds for good data acquisition and experimental times essential for practical usage of scarce XFEL beam times.

scholarly journals High-energy resolution X-ray absorption and emission spectroscopy reveals insight into unique selectivity of La-based nanoparticles for CO2

2015 ◽  
Vol 112 (52) ◽  
pp. 15803-15808 ◽  
Author(s):  
Ofer Hirsch ◽  
Kristina O. Kvashnina ◽  
Li Luo ◽  
Martin J. Süess ◽  
Pieter Glatzel ◽  
...  
Keyword(s):  
Energy Resolution ◽  
Emission Spectroscopy ◽  
High Energy ◽  
Unit Cell ◽  
High Energy Resolution ◽  
Electron Configuration ◽  
Edge Structure ◽  
X Ray ◽  
X Ray Absorption

The lanthanum-based materials, due to their layered structure and f-electron configuration, are relevant for electrochemical application. Particularly, La2O2CO3 shows a prominent chemoresistive response to CO2. However, surprisingly less is known about its atomic and electronic structure and electrochemically significant sites and therefore, its structure–functions relationships have yet to be established. Here we determine the position of the different constituents within the unit cell of monoclinic La2O2CO3 and use this information to interpret in situ high-energy resolution fluorescence-detected (HERFD) X-ray absorption near-edge structure (XANES) and valence-to-core X-ray emission spectroscopy (vtc XES). Compared with La(OH)3 or previously known hexagonal La2O2CO3 structures, La in the monoclinic unit cell has a much lower number of neighboring oxygen atoms, which is manifested in the whiteline broadening in XANES spectra. Such a superior sensitivity to subtle changes is given by HERFD method, which is essential for in situ studying of the interaction with CO2. Here, we study La2O2CO3-based sensors in real operando conditions at 250 °C in the presence of oxygen and water vapors. We identify that the distribution of unoccupied La d-states and occupied O p- and La d-states changes during CO2 chemoresistive sensing of La2O2CO3. The correlation between these spectroscopic findings with electrical resistance measurements leads to a more comprehensive understanding of the selective adsorption at La site and may enable the design of new materials for CO2 electrochemical applications.

scholarly journals Resonant inelastic X-ray scattering using a miniature dispersive Rowland refocusing spectrometer

2020 ◽  
Vol 27 (2) ◽  
pp. 446-454
Author(s):  
Alexander S. Ditter ◽  
William M. Holden ◽  
Samantha K. Cary ◽  
Veronika Mocko ◽  
Matthew J. Latimer ◽  
...  
Keyword(s):  
Energy Resolution ◽  
Emission Spectroscopy ◽  
Spot Size ◽  
High Energy ◽  
Extensive Study ◽  
High Energy Resolution ◽  
X Ray ◽  
X Ray Scattering ◽  
Scientific Mission ◽  
Ray Scattering

X-ray absorption spectroscopy (XAS) beamlines worldwide are steadily increasing their emphasis on full photon-in/photon-out spectroscopies, such as resonant inelastic X-ray scattering (RIXS), resonant X-ray emission spectroscopy (RXES) and high energy resolution fluorescence detection XAS (HERFD-XAS). In such cases, each beamline must match the choice of emission spectrometer to the scientific mission of its users. Previous work has recently reported a miniature tender X-ray spectrometer using a dispersive Rowland refocusing (DRR) geometry that functions with high energy resolution even with a large X-ray spot size on the sample [Holden et al. (2017). Rev. Sci. Instrum. 88, 073904]. This instrument has been used in the laboratory in multiple studies of non-resonant X-ray emission spectroscopy using a conventional X-ray tube, though only for preliminary measurements at a low-intensity microfocus synchrotron beamline. This paper reports an extensive study of the performance of a miniature DRR spectrometer at an unfocused wiggler beamline, where the incident monochromatic flux allows for resonant studies which are impossible in the laboratory. The results support the broader use of the present design and also suggest that the DRR method with an unfocused beam could have important applications for materials with low radiation damage thresholds and that would not survive analysis on focused beamlines.

scholarly journals Strain and ligand effects in Pt-Ni alloys studied by valence-to-core X-ray emission spectroscopy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jiatang Chen ◽  
Y. Zou Finfrock ◽  
Zhiqiang Wang ◽  
Tsun-Kong Sham
Keyword(s):  
Valence Band ◽  
Emission Spectroscopy ◽  
Compressive Strain ◽  
High Energy ◽  
Reduction Reaction ◽  
High Energy Resolution ◽  
Strain Effect ◽  
Ligand Effect ◽  
X Ray ◽  
Ni Alloys

AbstractExperimental detection of the Pt 5d densities of states in the valence band is conducted on a series of Pt-Ni alloys by high energy resolution valence-to-core X-ray emission spectroscopy (VTC-XES) at the Pt L3-edge. VTC-XES measurements reveal that the Pt d-band centroid shifts away from the Fermi level upon dilution, accompanied by concentration-dependent Pt d-band width. The competition between the strain effect and ligand effect is observed experimentally for the first time. It is found that the d-band widths in Pt3Ni and PtNi are broader than that of Pt metal due to compressive strain which overcompensates the effect of dilution, while it is narrower in PtNi3 where the ligand effect dominates. VTC-XES is demonstrated to be a powerful tool to study the Pt d-band contribution to the valence band of Pt-based bimetallic. The implication for the enhanced activity of Pt-Ni catalysts in oxygen reduction reaction is discussed.

Chemical speciation via X-ray emission spectroscopy in the tender X-ray range

2016 ◽  
Vol 31 (2) ◽  
pp. 450-457 ◽  
Author(s):  
Marko Petric ◽  
Matjaž Kavčič
Keyword(s):  
Energy Resolution ◽  
Emission Spectroscopy ◽  
Chemical Speciation ◽  
Full Range ◽  
Emission Spectra ◽  
High Energy ◽  
Oxidation States ◽  
High Energy Resolution ◽  
X Ray

Kα X-ray emission spectra from a series of phosphorus, sulfur, and chlorine containing compounds covering the full range of oxidation states were measured employing high energy resolution proton induced X-ray emission (PIXE) spectroscopy in the tender X-ray range.

Mn 2p resonant X-ray emission clarifies the redox reaction and charge-transfer effects in LiMn2O4

2019 ◽  
Vol 21 (33) ◽  
pp. 18363-18369 ◽  
Author(s):  
Daisuke Asakura ◽  
Yusuke Nanba ◽  
Eiji Hosono ◽  
Masashi Okubo ◽  
Hideharu Niwa ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Charge Transfer ◽  
Energy Resolution ◽  
Emission Spectroscopy ◽  
High Energy ◽  
High Energy Resolution ◽  
Transfer Effects ◽  
X Ray ◽  
Ion Extraction ◽  
Li Ion

High-energy-resolution soft X-ray emission spectroscopy (XES) was applied to understand the changes in the electronic structure of LiMn2O4 upon Li-ion extraction/insertion.

scholarly journals A high-throughput energy-dispersive tender X-ray spectrometer for shot-to-shot sulfur measurements

2019 ◽  
Vol 26 (3) ◽  
pp. 629-634 ◽  
Author(s):  
Baxter Abraham ◽  
Stanislaw Nowak ◽  
Clemens Weninger ◽  
Rebecca Armenta ◽  
Jim Defever ◽  
...  
Keyword(s):  
High Throughput ◽  
Energy Resolution ◽  
Free Electron ◽  
Free Electron Laser ◽  
High Energy ◽  
Emission Lines ◽  
Energy Dispersive ◽  
High Energy Resolution ◽  
X Ray ◽  
Sulfur Containing

An X-ray emission spectrometer that can detect the sulfur Kα emission lines with large throughput and a high energy resolution is presented. The instrument is based on a large d-spacing perfect Bragg analyzer that diffracts the sulfur Kα emission at close to backscattering angles. This facilitates the application of efficient concepts routinely employed in hard X-ray spectrometers towards the tender X-ray regime. The instrument described in this work is based on an energy-dispersive von Hamos geometry that is well suited for photon-in photon-out spectroscopy at X-ray free-electron laser and synchrotron sources. Comparison of its performance with previously used instrumentation is presented through measurements using sulfur-containing species performed at the LCLS. It is shown that the overall signal intensity is increased by a factor of ∼15. Implementation of this approach in the design of a tender X-ray spectroscopy endstation for LCLS-II is also discussed.

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