Surface-induced reactions of absorbed hydrogen under mutual mechanical forces

The present work describes a preliminary study of friction-induced surface reactions in ultra-high vacuum of H and D atoms adsorbed on stainless steel. Deuterium has been implanted in the sample by electrolysis of D2O. A pin with a ball end under controlled load produces the friction in alternating passes across the surface. A sample manipulator controls the normal and tangential loads of the pin on the surface. The spectra of the total pressure and ion current of H2+ as a function of friction time at different sweeping speeds are presented. Electron-stimulated desorption (ESD) has been used to verify the positive implantation of D atoms into the sample. The friction experiments on D-doped samples show that the reaction of the H and D surface atoms is to desorb as H2 and HD, i.e. second-order desorption. ESD also shows the presence of F and O species on the surface.