Grazing-incidence EXAFS

Grazing incidence EXAFS spectroscopic studies of Pb(II)aq adsorption on metal oxide surfaces - effect of differences in surface functional groups on reactivity... 

Bargar JR, Trainor TP, Fitts JP, Chambers SA, Brown GEJr (2002b) In situ grazing incidence EXAFS study of Pb(II) chemisorption on hematite (0001) and (1102). Langmuir (submitted). 

Waychunas GA, Reitmeyer R, Davis JA (2002) Grazing incidence EXAFS characterization of Fe3+ sorption and precipitation on silica surfaces, (submitted to J Col Inter Sci)... 

XANES spectroscopy is also the basis of chemically sensitive X-ray imaging, as well as qualitative and quantitative microspectroscopy [306], ptXANES is attractive for chemical analysis, with its spatial resolution down to 10 ptm. Variations on the theme are surface EXAFS (SEXAFS), grazing incidence XAS and in situ time-resolved XAS investigations. Grazing angle XAFS can be used for the study of ultrathin multilayer systems. 

XAS. In order to better understand the catal)4ic processes, we investigated Co nanoparticle catalysts in SAN and SiNW with grazing incidence X-ray absorption spectroscopy (GI-XAS). Figure 10.16 shows the results of EXAFS measurements. FT of the EXAFS of both SAN and SiNW samples are shown. 

Table 1. First neighbour numbers (N) and apparent first neighbour numbers (N ) for linear polarized light giving, in normal and grazing incidence, the different contributions to the EXAFS signal in the case of a full monolayer coverage. S—S indicates Co—Co bonds between two surface atoms and S—B (S—B ) indicates Co—Cu bonds between a surface atom and a first (second) underlayer atom, (p is the angle between the projection of the electric field in the surface plane and the nearest-neighbom bond direction in this plane.

Fig. 6a-c. One monolayer of cobalt on copper (111), grazing incidence, T = 77 K and T = 300 K relevant steps of the EXAFS analysis, a Experimental absorption spectra b fourier transform of the EXAFS oscillations c inverse Fourier transform of the first neighbour peak as a function of photoelectron kinetic energy E... 

Reich T, Moll H, Arnold T, Denecke MA, Hennig C, Geipei G, Bernhard G, Nitsche H, Allen PG, Bucher JJ, Edelstein NM, Shuh DK (1998) An EXAFS study of uranium(VI) sorption onto silica gel and ferrihydrite. J Electron Spectrosc Relat Phenom 96 237-243 Renaud G (1998) Oxide surfaces and metal/oxide interfaces studied by grazing incidence X-ray scattering. Surf Sci Rept 32 1-90... 

Lagarde P, Delaunay R, Flank AM, Jupille J (1993) Site of sulfur impurities in silicate glasses and REFLEXAFS studies around the Si -edge. Jap J Appl Phys 32 619-621 Lee PA, Citrin PH, Eisenberger PM (1981) Extended X-ray absoption fine structure-its strength and limitations as a structural tool. Rev Mod Phys 53 769-806 Lee JM, Yoo H-H, Joo M (1999) Numerical determination of a true absorption spectrum from grazing-incidence fluorescence EXAFS data. J Synchrotron Rad 6 244-246 Lieser KH, Flakowski M, Hoffman P (1994) Determination of trace elements in small water samples by total reflection X-ray fluorescence (TXRF) and by neutron activation analysis (NAA). Fresenius J Anal Chem 350 135-138... 

Figure 4. a) FT of the polarized Zn K-edge EXAFS k3y(k) spectra for undoped and indium doped ZnO films at normal (full line) and grazing (dashed line) incident angles, h) Polarized FeFF6 simulations with the X-ray polarization vector parallel to the [101] direction (full line) and to the [010] direction (dashed line). 

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