Quantitative determination of cerium oxidation states in alkali-aluminosilicate glasses using M4,5-edge XANES

A calibration method for quantitative determination of Ce4 +/Ce3 + in alkali-aluminosilicate glasses using Ce M4,5-edge X-ray absorption near edge structure (XANES) spectroscopy is presented. Samples of varying alkali oxide content synthesized over a range of temperatures and oxygen fugacities (fO2) were analyzed using both synchrotron-based XANES and traditional wet chemical techniques. Based on comparison to potentiometric determinations of Ce4 +/Ce3 + in digested portions of our samples, Ce4 + was found to have a greater fluorescence yield (FLY) response to the incident radiation in the M4,5-edge XANES region than Ce3 +. This results in an overestimation of the Ce4 +/Ce3 + ratio when directly comparing the contributions of the two oxidation states to the total M-edge area, as has been used for crystalline materials. We offer a correction to M-edge determined Ce4 +/Ce3 + ratios as follows:Ce4+/ΣCe=578.7Ce4+/ΣCe±5%XANESA±0.0040