Improved reproducibility of energy-dispersive X-ray microanalysis by normalization to the background

To improve the precision of energy-dispersive X-ray microanalysis it is proposed to normalize peak intensities to suitable regions of the background instead to the probe current. By such a ratio method several sources of errors are minimized. A formalism is given to convert measured peak to background ratios into concentrations. The method yields satisfactory results if specimens of similar composition are analyzed. Compositional differences of about 4 per mille (relative) could be clearly resolved in analyzing yttrium-iron-garnet single crystals. Several experimental aspects are outlined. (author)