X-ray, absorption scattering

Kahn, R., Fourme, R., Bosshard, R., Wery, J.P., Dideberg, O., Risler, J.L., Brunie, S. and Janin, J. (1984) Symposium on New Methods in X-ray Absorption Scattering and Diffraction for Applications in Structural Biology, Bristol. 

Laggner P FEBS Advanced Course Structure and Dynamics of Membrane Lipids April 1984, Zeist, Holland Symp. on New Methods in X-Ray Absorption, Scattering and Diffraction for Applications in Structural Biology , Aug. 1984, Bristol U.K. Chance B, Barttmik HD (eds) (1986) Academic Press, London... 

Moffat K, Bilderback D, Schildkamp W, Szebenyi D, Loane R (1986) In Chance B, Bartunik HD New methods in x-ray absorption, scattering and diffraction. Academic Press, New York, p 125... 

Almost every modem spectroscopic approach can be used to study matter at high pressures. Early experiments include NMR [ ], ESR [ ] vibrational infrared [33] and Raman [ ] electronic absorption, reflection and emission [23, 24 and 25, 70] x-ray absorption [Tf] and scattering [72], Mossbauer [73] and gems analysis of products recovered from high-pressure photochemical reactions [74]. The literature contains too many studies to do justice to these fields by describing particular examples in detail, and only some general mles, appropriate to many situations, are given. 

Rehr J J, Albers R C and Zabinski S I 1992 High order multiple scattering calculation of x-ray absorption fine structure Phys. Rev. Lett. 69 3397-400... 

FULL MULTIPLE SCATTERING CALCULATIONS ON HgTe UNDER HIGH PRESSURE AT THE MERCURY L3 X-RAY ABSORPTION EDGE... 

A detailed investigation of the structure of amorphous PcRu by large-angle X-ray scattering (LAXS)269 showed that in the solid state dimeric species exist with a Ru-Ru distance in the magnitude of a double bond. Current experiments using the extended X-ray absorption fine structure (EXAFS) method confirm these results.279... 

However, mathematics is essential to explain how structural data are derived from EXAFS. The EXAFS function, x(k), is extracted from the X-ray absorption spectrum in Fig. 4.10 by removing the approximately parabolic background and the step, i.e. the spectrum of the free atom. As in any scattering experiment, it is customary to express the signal as a function of the wavenumber, k, rather than of energy. The relation between k and the kinetic energy of the photoelectron is ... 

Surface extended X-ray absorption fine structure (SEXAFS). In order to understand the SEXAFS approach it may first be useful to give a brief recap of X-ray absorption. In addition to the scattering process described above, an X-ray photon may instead be absorbed. X-ray absorption results in the excitation of a core electron into one of the continuum of empty levels in the lowest unoccupied band of the sample this is shown for copper in Figure 2.72. To a first approximation, the attenuation of the beam is given by a form of the Beer-Lambert expression ... 

Berrodier, I., Farges, F., Benedetti, M., Winterer, M., Brown Jr, G. E., Deveughele, M. (2004). Adsorption mechanisms of trivalent gold on iron- and aluminum-(oxy)hydroxides. Part 1 X-ray absorption and Raman scattering spectroscopic studies of Au(III) adsorbed on ferrihydrite, goethite, and boehmite. Geochimica et Cosmochimica Acta, 68(14), 3019-3042. doi 10.1016/j.gca.2004.02.009... 

The electronic spin-state crossover in [Fe(HB(pz)3)2] has also been observed in the fine structure of its fC-edge x-ray absorption spectrum [38]. The changes in the x-ray absorption spectra of [Fe(HB(pz)3)2] are especially apparent between 293 and 450 K at ca. 25 eV, as is shown in Fig. 5. The 293 K x-ray absorption spectral profile observed in Fig. 5 for [Fe(HB(pz)3)2] has been reproduced [39] by a multiple photoelectron scattering calculation, a calculation that indicated that up to 33 atoms at distances of up to 4.19 A are involved in the scattering. As expected, the extended x-ray absorption fine structure reveals [38] no change in the average low-spin iron(II)-nitro-gen bond distance of 1.97 A in [Fe(HB(pz)3)2] upon cooling from 295 to 77 K. 

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