Chemical speciation of heterogeneously reduced Pu in synthetic brines

2006 ◽  
Vol 94 (5) ◽  
Author(s):  
Mei Ding ◽  
James L. Conca ◽  
Christophe Den Auwer ◽  
Rinat I. Gabitov ◽  
Nancy J. Hess ◽  
...  
Keyword(s):  
Fine Structure ◽  
New Mexico ◽  
Pilot Plant ◽  
Chemical Speciation ◽  
Speciation Analysis ◽  
Waste Isolation Pilot Plant ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Heterogeneous Reduction ◽  
X Ray Absorption

SummaryX-ray absorption fine structure (XAFS) spectroscopy has been used to determine the speciation of Pu precipitates prepared by the heterogeneous reduction of Pu(VI) with Al and Fe in 5 M NaCl and an ERDA-6 brine, a simulant from the Waste Isolation Pilot Plant in Carlsbad, New Mexico. NaOCl was added to some of these solutions to determine its effect on Pu speciation. Analysis of the Pu

Kinetic analysis of Ag particle redispersion into ZSM-5 in the presence of coke using in situ XAFS

2021 ◽  
Author(s):  
Kazumasa Murata ◽  
Junya Ohyama ◽  
Atsushi Satsuma
Keyword(s):  
Fine Structure ◽  
Kinetic Analysis ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Absorption Fine ◽  
Ag Particles ◽  
In Situ Xafs ◽  
Ag Particle ◽  
X Ray Absorption

In the present study, the redispersion behavior of Ag particles on ZSM-5 in the presence of coke was observed using in situ X-ray absorption fine structure (XAFS) spectroscopy.

X-Ray Absorption Fine Structure Study in FeTiO3

1997 ◽  
Vol 11 (16n17) ◽  
pp. 745-748 ◽  
Author(s):  
Rebekah Min-Fang Hsu ◽  
Kai-Jan Lin ◽  
Cheng Tien ◽  
Lin-Yan Jang
Keyword(s):  
Absorption Spectrum ◽  
Fine Structure ◽  
Absorption Spectra ◽  
Mixed Valence ◽  
Structure Study ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Absorption Fine ◽  
Trivalent State ◽  
X Ray Absorption

X-ray absorption fine structure XAFS spectroscopy has been used to determine the valence system for the Fe atom in ilmenite, FeTiO3 . This is the first XAFS data in FeTiO3 to our knowledge. The α- Fe2O3 data served as the standard in determining the ionization of the Fe atom in FeTiO3 . Observation of intensity and k-space are consistent. There was no evidence of mixed valence on comparing the FeTiO3 near edge X-ray absorption spectrum with α- Fe2O3 data. The absorption spectra suggest that iron is in the trivalent state in ilmenite.

scholarly journals Recent progress in the performance of HAPG based laboratory EXAFS and XANES spectrometers

2020 ◽  
Vol 35 (10) ◽  
pp. 2298-2304
Author(s):  
Christopher Schlesiger ◽  
Sebastian Praetz ◽  
Richard Gnewkow ◽  
Wolfgang Malzer ◽  
Birgit Kanngießer
Keyword(s):  
Fine Structure ◽  
Recent Progress ◽  
Pyrolytic Graphite ◽  
New Developments ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Absorption Fine ◽  
Mosaic Crystals ◽  
X Ray Absorption

New developments in the description and modeling of Highly Annealed Pyrolytic Graphite (HAPG) mosaic crystals have led to the possibility of designing optimized optical solutions for X-ray absorption fine structure (XAFS) spectroscopy.

Oxybarometry and valence quantification based on microscale X-ray absorption fine structure (XAFS) spectroscopy of multivalent elements

2020 ◽  
Vol 531 ◽  
pp. 119305 ◽  
Author(s):  
S.R. Sutton ◽  
A. Lanzirotti ◽  
M. Newville ◽  
M. Darby Dyar ◽  
J. Delaney
Keyword(s):  
Fine Structure ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Absorption Fine ◽  
X Ray Absorption

scholarly journals DAFNE-Light DXR1 Soft X-Ray Synchrotron Radiation Beamline: Characteristics and XAFS Applications

2019 ◽  
Vol 4 (1) ◽  
pp. 7 ◽  
Author(s):  
Antonella Balerna
Keyword(s):  
Fine Structure ◽  
Synchrotron Radiation ◽  
Disordered Systems ◽  
Beam Line ◽  
Long Range Order ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Insertion Device ◽  
Different Types ◽  
X Ray Absorption

X-ray Absorption Fine Structure Spectroscopy (XAFS) is a powerful technique to investigate the local atomic geometry and the chemical state of atoms in different types of materials, especially if lacking a long-range order, such as nanomaterials, liquids, amorphous and highly disordered systems, and polymers containing metallic atoms. The INFN-LNF DAΦNE-Light DXR1 beam line is mainly dedicated to soft X-ray absorption spectroscopy; it collects the radiation of a wiggler insertion device and covers the energy range from 0.9 to 3.0 keV or the range going from the K-edge of Na through to the K-edge of Cl. The characteristics of the beamline are reported here together with the XAFS spectra of reference compounds, in order to show some of the information achievable with this X-ray spectroscopy. Additionally, some examples of XAFS spectroscopy applications are also reported.

Bent crystal Laue analyser combined with total reflection fluorescence X-ray absorption fine structure (BCLA + TRF-XAFS) and its application to surface studies

2020 ◽  
Vol 27 (6) ◽  
pp. 1618-1625
Author(s):  
Yuki Wakisaka ◽  
Bing Hu ◽  
Daiki Kido ◽  
Md. Harun Al Rashid ◽  
Wenhan Chen ◽  
...  
Keyword(s):  
Fine Structure ◽  
Sudden Change ◽  
Fluorescence Emission ◽  
Total Reflection ◽  
X Rays ◽  
X Ray ◽  
Xafs Spectroscopy ◽  
Bent Crystal ◽  
Absorption Fine ◽  
X Ray Absorption

A bent crystal Laue analyser (BCLA) is an X-ray energy analyser used for fluorescence X-ray absorption fine-structure (XAFS) spectroscopy to separate the fluorescence X-ray emission line of a target atom from the elastic scattering X-rays and other fluorescence emission lines. Here, the feasibility of the BCLA for total reflection fluorescence XAFS (TRF-XAFS), which has a long X-ray footprint on the substrate surface owing to grazing incidence, was tested. The focal line of the BCLA was adjusted on the X-ray footprint and the XAFS signal for one monolayer of Pt deposited on a 60 nm Au film with high sensitivity was obtained. Although range-extended XAFS was expected by the rejection of Au fluorescence arising from the Au substrate, a small glitch was found in the Au L 3 edge because of the sudden change of the complex refraction index of the Au substrate at the Au edge. This abnormal spectrum feature can be removed by reflectivity correction using Au foil absorption data. BCLA combined with TRF-XAFS spectroscopy (BCLA + TRF-XAFS) is a new technique for the in situ surface analysis of highly dispersed systems even in the presence of a liquid overlayer.

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