Showing papers in "Chemia Analityczna in 1988"

X-ray absorption : principles, applications, techniques of EXAFS, SEXAFS, and XANES

Abstract: Theory of EXAFS. Theory of XANES. INSTRUMENTAL AND DATA ANALYSIS. Design of an EXAFS Experiment. EXAFS with Synchrotron Radiation. Laboratory EXAFS Facilities. Data Analysis. APPLICATIONS. Biochemical Application of X-ray Absorption Spectroscopy. Catalysis. Amorphous and Liquid Systems. SEXAFS. XANES Spectroscopy.

Laboratory EXAFS Facilities

Abstract: This chapter has demonstrated that high quality XANES and EXAFS spectra can be collected with laboratory EXAFS facilities The limitations of these facilities have been discussed and it has been shown that synchrotronlike reso lutions, which are sometimes claimed by enthusiastic supporters of synchrotron facilities to be essential for deriving reliable structural EXAFS information, are not necessary Resolutions of 10—15 eV can still be expected XANES spectra can be measured with synchrotronlike resolutions within an acceptable time of 1—2 h At this moment only a few papers dealing with the analysis of high quality laboratory EXAFS data have been published Laboratory EXAFS spectrometers, fully optimized according to the points discussed in Section 553, have not yet been reported in the literature A key point in this optimization process is the production of high quality monochromator crystals of large (horizontal) dimen sions No large scale applications for laboratory EXAFS facilities are foreseen, if this optimization does not take place and if intensities impinging on the sample remain lower than i07 photons s ‘ (bandpass 5—15 eV) However, the technol ogies available nowadays can bring such an optimization to reality and many experimentalists may then make fruitful use of their laboratory EXAFS facility