It was shown that the optical indicator technique, used to visualize fast H migration in thin metal films, could also be used in an electrochemical set-up. The lateral diffusion of H in a V film under a masking layer could be monitored by using optical changes, in an Y switchable mirror, which served as an indicator of the diffusion front. An electrochemical loading experiment provided a precise measure of the total H content of the sample. Optical reflectance measurements permitted the determination of the H diffusion coefficient. The electrochemical set-up was also used to measure the room-temperature solubility isotherm of the film. It was found that the observed miscibility gap was smaller than that of the bulk metal.

Electrochemical Study of Hydrogen Diffusion in a Vanadium Thin Film. M.Di Vece, A.Remhof, J.J.Kelly: Electrochemistry Communications, 2004, 6[1], 17-21