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 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.

In situ observation of charge transfer and crystal field formation via high energy resolution X-ray spectroscopy during temperature programmed oxidation

2020 ◽  
Vol 22 (26) ◽  
pp. 14731-14735
Author(s):  
Anna Wach ◽  
Wojciech Błachucki ◽  
Joanna Czapla-Masztafiak ◽  
Daniel Luis Abreu Fernandes ◽  
Dariusz Banaś ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Energy Resolution ◽  
High Energy ◽  
High Energy Resolution ◽  
In Situ Observation ◽  
X Ray ◽  
Temperature Programmed Oxidation ◽  
Temperature Programmed ◽  
Charge Transfer Dynamics ◽  
Field Formation

In this paper, we demonstrated how high energy resolution resonant X-ray emission spectroscopy can be employed to study the charge transfer dynamics in real-time during the temperature-induced oxidation of metallic tungsten.

scholarly journals High-energy resolution X-ray spectroscopy at actinide M4,5 and ligand K edges: what we know, what we want to know, what we can know

2021 ◽  
Author(s):  
Kristina Kvashnina ◽  
Sergei M Butorin
Keyword(s):  
Electronic Structure ◽  
Energy Resolution ◽  
Chemical Properties ◽  
High Energy ◽  
High Energy Resolution ◽  
X Ray

In recent years, scientists have progressively recognized the role of electronic structure in the characterization of chemical properties for actinide containing materials. High-energy resolution X-ray spectroscopy at the actinide M4,5...

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.

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