Oxygen adsorption induced hydrogen segregation on a zirconium surface

The adsorption process of oxygen on a Zr surface was studied by a time-of-flight electron-stimulated desorption TOF-ESD.method. Oxygen adsorption induced hydrogen segregation on the Zr surface. It was revealed that the increase in Hq yield following O2 exposure is not caused by adsorption from the gas phase but by the diffusion of H from the bulk of Zr. In addition, H atoms formed Zr`H bonds rather than hydroxyl species. From the analysis of the experimental results, it is suggested that O atoms penetrating into the Zr sample substitute for H atoms at tetrahedral sites, causing the diffusion of H atoms. q2000 Published by Elsevier Science B.V.