DETERMINATION OF INNER-SHELL CROSS-SECTIONS FOR EELS-QUANTIFICATION

Quantitative microanalysis using the EELS technique requires the knowledge of partial scattering cross-sections to relate the measured intensities to the concentrations in the compounds. Partial scattering cross-sections can be determined either theoretically or empirically by means of standards. Cross-sections for K, L23 and M45 ionization edges can be calculated by the hydrogenic model and by the Hartree-Slater-model and with these models elements ranging from Li to W can be quantified. Alternatively, the ratio of two cross-sections (k-factor) can be used for quantification. These k-factors can be determined by measuring the appropriate ionization edges using a thin film standard, which has been done for K, L23, M45 and N45-edges. Scattering cross-sections which have been determined by these methods are compared and their impact on the reliability and accuracy of EELS-quantification is critically discussed.