Water dissociation and selective absorption in the Zr[V0.5Fe0.5]2 gettering alloy: An X-ray photoemission spectroscpoy investigation

We report a study, based on x-ray photoemission spectroscopy, on the effects of element-specific selective absorption of the nonevaporable @Zr~V0.5Fe0.5!2# gettering alloy after massive exposure to water vapor ~33103 Pa for '2000 h at 400 °C!. The specimens have been analyzed both after scraping and along a prolonged Ar1 sputtering in order to comparatively discriminate intergranular versus intragranular properties. Oxygen is found to diffuse into the bulk of the alloy grains giving a distribution of Zr oxides where ZrO2 is the major component. After removal of the outermost atomic layers, Fe and V show a major metallic character in the alloy volume. Traces of Zr hydroxides are also seen. The virgin ~nonwater treated! @Zr~V0.5Fe0.5!2# alloy has also been comparatively measured.