Contribution of the surface contamination of uranium materials on the quantitative analysis results by electron probe microbeam analysis

The first part of this paper is devoted to the study of contaminated surface of the uranium materials U, UFe2 and U6Fe a few hours after the preparation. These oxidation conditions are selected with the aim to reproduce the same contamination surfaces that occurred in microprobe analytical conditions. The surface characterization techniques are SIMS and Auger spectroscopy. The contaminated surfaces are described. They are made of successive layers: a carbon layer, one oxidized iron layer followed by an iron depletion layer (only in UFe2 and U6Fe), and a ternary oxide layer (U-Fe-O for UFe2 et U6Fe and UO2+x for the uranium). The second part of this paper is devoted to estimating errors caused by surface contamination during quantitative analysis. EPMA-WDS is used to make the estimation. The analyses were carried out with a CAMECA SX100 and the simulation with the X-Film software.