Surface phenomena in the process of vanadium hydride formation

Surface phenomena associated with the formation of vanadium hydride VHx were studied by measuring both the surface potential of thin V films and the H-2 pressure during hydrogen interaction with vanadium. It has been found that hydrogen forms two different adspecies here referred to as beta(-) and beta(+). The beta(+) adspecies forms a precursor in the fast incorporation process of atoms from the surface into the bulk of the metal. The bcc to fee phase transition which occurs during the VHx formation alters the kinetics of beta(+) incorporation. On the surface of V-0.6 a weakly bound atomic hydrogen adsorbate was found at 87 K under a H-2 pressure of the order of VH0.6 Pa.