Electronic and Chemical State of Aluminum from the Single- (K) and Double-Electron Excitation (KLII&III, KLI) X-ray Absorption Near-Edge Spectra of α-Alumina, Sodium Aluminate, Aqueous Al3+·(H2O)6, and Aqueous Al(OH)4–

2015 ◽  
Vol 119 (26) ◽  
pp. 8380-8388 ◽  
Author(s):  
John L. Fulton ◽  
Niranjan Govind ◽  
Thomas Huthwelker ◽  
Eric J. Bylaska ◽  
Aleksei Vjunov ◽  
...  
Keyword(s):  
Electron Excitation ◽  
Sodium Aluminate ◽  
Chemical State ◽  
X Ray ◽  
Double Electron ◽  
X Ray Absorption

EXELFS Studies of Carbon Fibers

1990 ◽  
Vol 48 (2) ◽  
pp. 72-73
Author(s):  
V. Serin ◽  
K. Hssein ◽  
G. Zanchi ◽  
J. Sévely
Keyword(s):  
Carbon Fibers ◽  
Energy Analysis ◽  
Electron Excitation ◽  
Complex Structures ◽  
High Modulus ◽  
Promising Technique ◽  
X Ray ◽  
Fine Structures ◽  
X Ray Absorption

The present developments of electron energy analysis in the microscopes by E.E.L.S. allow an accurate recording of the spectra and of their different complex structures associated with the inner shell electron excitation by the incident electrons (1). Among these structures, the Extended Energy Loss Fine Structures (EXELFS) are of particular interest. They are equivalent to the well known EXAFS oscillations in X-ray absorption spectroscopy. Due to the EELS characteristic, the Fourier analysis of EXELFS oscillations appears as a promising technique for the characterization of composite materials, the major constituents of which are low Z elements. Using EXELFS, we have developed a microstructural study of carbon fibers. This analysis concerns the carbon K edge, which appears in the spectra at 285 eV. The purpose of the paper is to compare the local short range order, determined by this way in the case of Courtauld HTS and P100 ex-polyacrylonitrile carbon fibers, which are high tensile strength (HTS) and high modulus (HM) fibers respectively.

Chemical State and Local Structure around Titanium Atoms in NaAlH4Doped with TiCl3Using X-ray Absorption Spectroscopy

2004 ◽  
Vol 108 (42) ◽  
pp. 16372-16376 ◽  
Author(s):  
Aline Léon ◽  
Oliver Kircher ◽  
Jörg Rothe ◽  
Maximilian Fichtner
Keyword(s):  
Absorption Spectroscopy ◽  
Local Structure ◽  
Chemical State ◽  
X Ray ◽  
State And Local ◽  
X Ray Absorption

scholarly journals Novel sub-eV high throughput laboratory micro-XAS (x-ray absorption spectrometer) for chemical state analysis through XANES and EXAFS

2018 ◽  
Vol 24 (S1) ◽  
pp. 1008-1009
Author(s):  
Wenbing Yun ◽  
Srivatsan Seshadri ◽  
Sylvia Lewis ◽  
Jeff Gelb ◽  
SH Lau ◽  
...  
Keyword(s):  
High Throughput ◽  
Chemical State ◽  
X Ray ◽  
X Ray Absorption ◽  
Absorption Spectrometer ◽  
State Analysis

Direct Correlation of Solar Cell Performance with Metal Impurity Distributions in Polycrystalline Silicon using Synchrotron-Based X-ray Analysis

1998 ◽  
Vol 524 ◽  
Author(s):  
S. A. McHugo ◽  
A. C. Thompson ◽  
G. Lamble ◽  
A. MacDowell ◽  
R. Celestre ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Polycrystalline Silicon ◽  
Current Method ◽  
Chemical State ◽  
Limiting Factors ◽  
Metal Impurity ◽  
Solar Cell Performance ◽  
X Ray ◽  
X Ray Absorption

ABSTRACTThe work presented here directly measures metal impurity distributions and their chemical state in as-grown and fully processed polycrystalline silicon used for terrestrial-based solar cells. The goal was to determine if a correlation exists between poorly performing regions of solar cells and metal impurity distributions as well as to ascertain the chemical state of the impurities. Synchrotron-based x-ray fluorescence mapping and x-ray absorption spectroscopy, both with a spatial resolution of lμm, were used to measure impurity distributions and chemical state, respectively, in poorly performing regions of polycrystalline silicon. The Light Beam Induced Current method was used to measure minority carrier recombination in the material in order to identify poor performance regions. We have detected iron, chromium, nickel, gold and copper impurity precipitates and we have recognized a direct correlation between impurity distributions and poor performing regions in both as-grown and fully processed material. Furthermore, from x-ray absorption studies, we have initial results, indicating that the Fe in this material is in oxide form, not FeSi2,. These results provide a fundamental understanding into the efficiency-limiting factors of polycrystalline silicon solar cells as well as yielding insight for methods of solar cell improvement.

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