XPS study of hydrogen and oxygen interactions on the surface of zirconium

Abstract The purpose of this study is to investigate the role of temperature and hydrogen charging conditions on hydrogen and oxygen dissolution and segregation on the surface of zirconium. X-Ray photoelectron spectroscopy was used to follow the changes as a function of temperature in the electronic properties of the surface before and after in situ or ex situ exposure to hydrogen. In situ annealing of Zr samples favors the oxygen decontamination of the surface and increases its reactivity with H. In situ (gas) or ex situ (cathodic) exposure of Zr to hydrogen at 20 °C promotes the nucleation of a Zr hydride on the surface which decomposes with increasing the temperature up to 600 °C. A segregation of oxygen on the surface is also associated with the local hydrogen enrichment.