IONIZATION CROSS-SECTIONS FOR THE L(23)-EDGES OF THE ELEMENTS SR TO MO FOR QUANTITATIVE EELS ANALYSIS

Quantitative microanalysis by electron energy-loss spectrometry requir es knowledge of partial inner-shell ionization cross-sections. Data fo r the L(23)-edges of the elements strontium to molybdenum are not well known. We have therefore measured cross-section ratios (k-factors) fo r the L(23)-edges of the elements Sr to Mo using thin film oxide-stand ards. The experimental values are compared with calculations derived f rom a modified hydrogenic and a Hartree-Slater model. The results are presented in terms of an integrated dipole oscillator strength to faci litate both comparisons between theory and experiment, and calculation s of cross-sections for particular experimental conditions. While hydr ogenic theory oscillator-strength values deviate from the experimental ones by more than 30%, there is good agreement between Hartree-Slater theory and experiment. We have also compared the relative microanalyt ical sensitivities for the M(45)- and L(23)-ionization edges of these elements.