L edge

Figure 7 Microanalysis of a CuO/ZnO methanol synthesis catalyst with a field-emission STEM (a) EOS data showing Cu and Zn K-lines and (b) EELS data showing Cu and Zn L-edges with dotted lines indicating background levels. Spectra were taken simultaneously from a 2-nm diameter area. Signal intensities above background show that approximately the same relative amounts of Cu and Zn were measured by each method.

Figure 2 Surface EXAFS spectra above the Pd L edge for a 1.5 monolayer evaporated film of Pd on Sid 11) and for bulk palladium ailicide, Pd2Si and metallic Pd.

The accuracy achievable by the ratio method amounts to approximately 5-10 atom% when ionization edges of the same type are used, i. e. only K edges or only L edges, whereas the error in quantification increases to +15-20 atom% for the use of dissimilar edges. Improvement of the quantification accuracy up to approximately 1 atom% is possible if standards are used. 

Data obtained from EXAFS measurements except X (X-ray). From Os L-edge From Br K-edge. 

For each measurement 2 to 3 scans were averaged over a total time of V 40 minutes. Temperatures were measured and kept constant at the temperatures Indicated to +5°C. An example of raw data for 2.5 pm thick Ft foil at 298 K Is shown In figure 1. The three L-edges of Pt are shown, with the zero of energy at 11,563.7 eV, the position of... 

The Fine Structure Before and After Each Edge. ELNES is the term use to describe the energy-loss near edge structure, and this can be quite different for an element in different compounds. For example the shape of the aluminium L edges are quite different in EELS spectra from metallic aluminium and aluminium oxide, so that the chemical form of a given element may be indentified from these small variations in intensity after the edge. 

Fig. 20 As L -edge XANES spectrum for CrAs, measured in fluorescence mode. Reprinted with permission from [61]. Copyright Elsevier...

Fig. 16.7 Plutonium L -edge XANES spectra plotted with respect to the relative XANES edge energy for sorbed Pu on Yucca Mountain tuff at 6 months and 2 years. All spectra taken after two years indicated an average oxidation state of Pu(IV) those taken after 6 months had average oxidation states predominantly of Pu(V) and Pu(VI). Reprinted with permission from Powell BA, Duff MC, Kaplan DI, Field RA, Newville M, Hunter BD, Bertsch PM, Coates JT, Serkiz SM, Sutton RS, Triay IR, Vaniman DT (2006) Plutonium oxidation and subsequent reduction by Mn(IV) minerals in Yucca Mountain tuff. Environ Sci Technol 40 3508-3514. Copyright 2006 American Chemical Society...

Figure 8.1 Theoretically calculated f and f" values as a function of wavelength in the vicinity of the K absorption edge of selenium (a) and the L edge of holmium (b).

Figure 8.2 Theoretically calculated f and f" curves In the neighbourhood of the L edges of europium (solid line) and gold (dashed line) are shown. Wavelengths that were chosen for measurement of peak, Inflection point and remote data in each case are marked by arrows and labelled.

Figure 1. Normalised absorption at the Pt L edges boxes experimental data full lines calculated Lorentzian contribution, arctangent contribution and complete equation (1).

Table I. White-line surface areas from deconvolution of the platinum L edges...

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