Oxygen adsorption induced hydrogen segregation on a zirconium surface

The adsorption process of oxygen on a Zr surface was studied by a time-of-f light electron-stimulated desorption (TOF-ESD) method. Oxygen adsorption in duced hydrogen segregation on the Zr surface. It was revealed that the incr ease in H+ yield following O-2 exposure is not caused by adsorption from th e gas phase but by the diffusion of H from the bulk of Zr. In addition, I-I atoms formed Zr-H bonds rather than hydroxyl species. From the analysis of the experimental results, it is suggested that O atoms penetrating into th e Zr sample substitute for ii atoms at tetrahedral sites, causing the diffu sion of H atoms. (C) 2000 Published by Elsevier Science B.V.