Spatially-Resolved X-Ray Absorption fine Structure (XAFS) Spectroscopy Using Undulator Radiation Focused by Dynamically-Bent Elliptical Mirrors

X-ray absorption spectroscopy (XANES and EXAFS) applied with x-ray microprobe instrumentation (figures 1) can be used for studying the electronic structure of specific elements in complex materials in a spatially-resolved manner (figure 2). Such techniques are valuable in a wide range of studies including hydrothermal fluid processes, migration and encapsulation of toxic and radioactive wastes, and redox evolution of solar system bodies.One of the major technical challenges in this work is the production of high flux microbeams from high power, hard x-ray synchrotron sources. Some of the microbeam technologies under development include tapered glass capillaries, zone plates, and elliptical mirrors. Each approach has advantages and disadvantages and the optimum microfocusing device depends on the particular experiment.One of the most versatile of these devices is the dynamically bent, elliptical mirror, especially when a pair of mirrors are arranged in a Kirkpatrick-Baez (KB) geometry to provide two-dimensional focusing. This versatility derives mainly from four attributes.

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

Catalysis Science & Technology ◽

10.1039/d0cy01989e ◽

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.

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Distributed X-ray photon correlation spectroscopy data reduction using Hadoop MapReduce

Journal of Synchrotron Radiation ◽

10.1107/s160057751800601x ◽

2018 ◽

Vol 25 (4) ◽

pp. 1135-1143 ◽

Cited By ~ 6

Author(s):

Faisal Khan ◽

Suresh Narayanan ◽

Roger Sersted ◽

Nicholas Schwarz ◽

Alec Sandy

Keyword(s):

Real Time ◽

Photon Correlation Spectroscopy ◽

Correlation Spectroscopy ◽

Frame Rate ◽

Computational Techniques ◽

Complex Materials ◽

Photon Correlation ◽

X Ray ◽

Wide Range ◽

Recent Developments

Multi-speckle X-ray photon correlation spectroscopy (XPCS) is a powerful technique for characterizing the dynamic nature of complex materials over a range of time scales. XPCS has been successfully applied to study a wide range of systems. Recent developments in higher-frame-rate detectors, while aiding in the study of faster dynamical processes, creates large amounts of data that require parallel computational techniques to process in near real-time. Here, an implementation of the multi-tau and two-time autocorrelation algorithms using the Hadoop MapReduce framework for distributed computing is presented. The system scales well with regard to the increase in the data size, and has been serving the users of beamline 8-ID-I at the Advanced Photon Source for near real-time autocorrelations for the past five years.

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X-Ray Absorption Fine Structure Study in FeTiO3

Modern Physics Letters B ◽

10.1142/s0217984997000918 ◽

1997 ◽

Vol 11 (16n17) ◽

pp. 745-748 ◽

Cited By ~ 4

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.

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Time and Spatially Resolved Study of Fuel Cell Reactions Using In situ X-ray Absorption Spectroscopy

ECS Meeting Abstracts ◽

10.1149/ma2011-01/42/1983 ◽

2011 ◽

Keyword(s):

Fuel Cell ◽

Absorption Spectroscopy ◽

X Ray ◽

Spatially Resolved ◽

X Ray Absorption

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Spatially Resolved Characterization of Biogenic Manganese Oxide Production within a Bacterial Biofilm

Applied and Environmental Microbiology ◽

10.1128/aem.71.3.1300-1310.2005 ◽

2005 ◽

Vol 71 (3) ◽

pp. 1300-1310 ◽

Cited By ~ 94

Author(s):

Brandy Toner ◽

Sirine Fakra ◽

Mario Villalobos ◽

Tony Warwick ◽

Garrison Sposito

Keyword(s):

Careful Consideration ◽

Bacterial Biofilm ◽

Bacterial Cells ◽

X Ray ◽

Spatially Resolved ◽

Nexafs Spectroscopy ◽

Promising Tool ◽

Scanning Transmission ◽

X Ray Absorption

ABSTRACT Pseudomonas putida strain MnB1, a biofilm-forming bacterial culture, was used as a model for the study of bacterial Mn oxidation in freshwater and soil environments. The oxidation of aqueous Mn+2 [Mn+2 (aq)] by P. putida was characterized by spatially and temporally resolving the oxidation state of Mn in the presence of a bacterial biofilm, using scanning transmission X-ray microscopy (STXM) combined with near-edge X-ray absorption fine structure (NEXAFS) spectroscopy at the Mn L2,3 absorption edges. Subsamples were collected from growth flasks containing 0.1 and 1 mM total Mn at 16, 24, 36, and 48 h after inoculation. Immediately after collection, the unprocessed hydrated subsamples were imaged at a 40-nm resolution. Manganese NEXAFS spectra were extracted from X-ray energy sequences of STXM images (stacks) and fit with linear combinations of well-characterized reference spectra to obtain quantitative relative abundances of Mn(II), Mn(III), and Mn(IV). Careful consideration was given to uncertainty in the normalization of the reference spectra, choice of reference compounds, and chemical changes due to radiation damage. The STXM results confirm that Mn+2 (aq) was removed from solution by P. putida and was concentrated as Mn(III) and Mn(IV) immediately adjacent to the bacterial cells. The Mn precipitates were completely enveloped by bacterial biofilm material. The distribution of Mn oxidation states was spatially heterogeneous within and between the clusters of bacterial cells. Scanning transmission X-ray microscopy is a promising tool for advancing the study of hydrated interfaces between minerals and bacteria, particularly in cases where the structure of bacterial biofilms needs to be maintained.

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

Journal of Analytical Atomic Spectrometry ◽

10.1039/d0ja00208a ◽

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.

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Near Edge X-Ray Absorption Fine Structure (NEXAFS) Microscopy: Chemical Analysis at Sub Visible Spatial Resolution

Microscopy and Microanalysis ◽

10.1017/s1431927600011144 ◽

1997 ◽

Vol 3 (S2) ◽

pp. 851-852

Author(s):

H. Ade

Keyword(s):

Fine Structure ◽

Compositional Analysis ◽

High Sensitivity ◽

Linear Dichroism ◽

X Rays ◽

X Ray ◽

Absorption Fine ◽

Nexafs Spectroscopy ◽

Wide Range ◽

X Ray Absorption

Infrared, Raman, and fluorescence/luminescence microspectroscopy/microscopy in many instances seek to provide high sensitivity compositional and functional information that goes beyond mere elemental composition. This goal is shared by NEXAFS microscopy, in which Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy is employed to provide chemical sensitivity and can be relatively easily adopted in a scanning transmission x-ray microscope (STXM). In addition to compositional information, NEXAFS microscopy can exploit the dependence of x-ray absorption resonances on the bond orientation relative to the linearly polarized x rays (linear dichroism microscopy). For compositional analysis, NEXAFS microscopy is analogous to Electron Energy Loss Spectroscopy (EELS) in an electron microscope. However, when utilizing near edge spectral features, NEXAFS microscopy requires a considerable lower dose than EELS microscopy which makes it very suitable to studying radiation sensitive materials such as polymers. NEXAFS has shown to have excellent sensitivity to a wide range of moieties in polymers, including sensitivity to substitution isomerism.

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Phosphorus L 2,3-edge XANES: overview of reference compounds

Journal of Synchrotron Radiation ◽

10.1107/s0909049509000211 ◽

2009 ◽

Vol 16 (2) ◽

pp. 247-259 ◽

Cited By ~ 60

Author(s):

Jens Kruse ◽

Peter Leinweber ◽

Kai-Uwe Eckhardt ◽

Frauke Godlinski ◽

Yongfeng Hu ◽

...

Keyword(s):

Spectral Features ◽

Edge Structure ◽

Complex Samples ◽

Distinctive Features ◽

X Ray ◽

Wide Range ◽

Element Speciation ◽

Unknown Composition ◽

Almost All ◽

X Ray Absorption

Synchrotron-based X-ray absorption near-edge structure (XANES) spectroscopy is becoming an increasingly used tool for the element speciation in complex samples. For phosphorus (P) almost all XANES measurements have been carried out at the K-edge. The small number of distinctive features at the P K-edge makes in some cases the identification of different P forms difficult or impossible. As indicated by a few previous studies, the P L 2,3-edge spectra were richer in spectral features than those of the P K-edge. However, experimentally consistent spectra of a wide range of reference compounds have not been published so far. In this study a library of spectral features is presented for a number of mineral P, organic P and P-bearing minerals for fingerprinting identification. Furthermore, the effect of radiation damage is shown for three compounds and measures are proposed to reduce it. The spectra library provided lays a basis for the identification of individual P forms in samples of unknown composition for a variety of scientific areas.

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