EXAFS can be used to characterise the phase of an amorphous calcified deposit mixed with a crystalline phase which does not contain calcium. In such a mixture, the amorphous phase may not be detectable by X-ray diffraction. This application of EXAFS is illustrated by the characterisation of the calcium phosphate deposited in association with struvite in encrusted urinary catheters.

16 LLE Review, Volume 97 Introduction Recently, x-ray diffraction has been used to study dynamic material response to shocks of high pressure (~0.1 to 1 Mbar) and high strain rate (~107 to 108 s−1).1–3 The goal of this work is to demonstrate the use of extended x-ray absorption fine structure (EXAFS)4 as a complementary characterization of such laser-shocked metals. EXAFS is the modulation in t...

1.59.1 PHYSICS OF X-RAY ABSORPTION 1 1.59.1.1 X-ray Absorption Edges 2 1.59.1.2 X-ray Fluorescence 3 1.59.1.3 Measurement of X-ray Absorption Spectra 3 1.59.2 EXTENDED X-RAY ABSORPTION FINE STRUCTURE 6 1.59.2.1 Theoretical Description of EXAFS Spectra 6 1.59.2.1.1 Single scattering 6 1.59.2.1.2 Multiple scattering 8 1.59.2.1.3 Other corrections to the EXAFS equation 9 1.59.2.2 Programs for Calc...

We discuss methods of Extended X-ray Absorption Fine-Structure (EXAFS) analysis that provide three-dimensional structural characterization of metal nanoparticles, both monoand bi-metallic. For the bimetallic alloys, we use short range order measurements to discriminate between random and non-random inter-particle distributions of atoms. We also discuss the application of EXAFS to heterogeneous ...

The effect of polydispersity and inhomogeneity of supported bimetallic catalysts on the EXAFS analysis is investigated with some simple model calculations. These show that EXAFS is very insensitive to polydispersity. Polydispersity and inhomogeneous distribution of the metals over the particles however have only limited influence on the ability to distinguish between core-shell particles and pa...

The stability against crystallization of the amorphous phase‐change materials (CGT) exhibits an unusual behavior at low Cu concentrations with being most stable composition. Three CGT compositions , 15, and 25 are analyzed using extended X‐ray absorption fine structure (EXAFS) Ge‐K, Cu‐K, Te‐K edge 10 K. EXAFS analysis shows that average coordination number (CN) increases concentration from 2.8...

In a recent extended x-ray absorption fine structure (EXAFS) analysis of icosahedral and a-phases of AlMnSi it was shown frgm the Mn-Mn scattering that an icosahedron cage of Mn atoms with edge length 2 5 A is the structural unit in the icosahedral phase. In this paper we present results on the radial distribution function (RDF) of the first shell A1 atoms yielded by a direct Fourier transform ...

A description and comparison of various EXAFS-like phenomena are presented based on theoretical and practical considerations. Most of the phenomena are similar but not exactly the same as EXAFS. This does not limit their usefulness for structure determination but requires separate experimental calibration and theoretical calculations.

The distribution of Ga and A1 atoms within the octahedral sheets of synthetic goethites has been investigated by XRD and Ga K-edge XANES and EXAFS spectroscopies. XRD results indic te a solid solution between goethite (aFeOOH) and GaGoe4 (40 mol% of Ga). The XANES data indicate the presence of &a in the solid solution. The fitting procedures for EXAFS spectra show no evidence of preferential oc...