Testing the accuracy of low-beam-energy electron-excited X-ray microanalysis with energy-dispersive spectrometry

The accuracy of electron-excited X-ray microanalysis with energy-dispersive spectrometry (EDS) has been tested in the low beam energy range, specifically at an incident beam energy of 5 keV, which is the lowest beam energy for which a useful characteristic X-ray peak can be excited for all elements of the periodic table, excepting H and He. Elemental analysis results are reported for certified reference materials (CRM), stoichiometric compounds, minerals, and metal alloys of independently known or measured composition which had microscopic homogeneity suitable for microanalysis. Two-hundred sixty-three concentration measurements for 39 elements in 113 materials were determined following the k-ratio protocol and using the EDS analytical software NIST DTSA-II. The accuracy of the results, as characterized by the relative deviation from expected value (RDEV) metric, was such that more than 98% of the results were found to be captured within a range of ±5% RDEV, while 82% of the results fell in the range -2% to 2% RDEV.