Measurements of relative x-ray line intensities and their application to a single standard procedure for quantitative x-ray microanalysis

Abstract

X-ray spectra collected by an energy dispersive spectrometer on an electron microprobe analyzer were deconvoluted to determine relative line intensities between elements for a wide range of atomic numbers. The relative line intensities within spectral series for K, L, and M lines were also obtained. In the case of Kα lines an empirical formula is proposed for the prediction of generated line intensities of pure element standards relative to that of CuKα at 20keV used as a reference standard, although other line references can be used for lower beam energies. The generated ratios can be predicted with accuracy generally better than 2% relative to the actual measured values. The relationship covers elements with atomic numbers in the range of 12 (Mg) to 32 (Ge) and incident beam energies between 5 and 20keV. Unfortunately, L and M line data could not be fitted with the same level of accuracy to a single expression due to the inherent scatter in the data as a function of atomic number. These data are therefore presented in tabular form. The availability of relative line intensity measurements as a function of atomic number makes it possible to perform accurate quantitative x-ray microanalysis with the measurement of a single standard rather than a separate measurement of each element standard. As a result not only are measurement times shorter, but it is also possible to estimate values for elements for which pure standards may not be available. Furthermore, the method has been extended to quantitative analysis based only on the measurement of the sample spectrum.