INTERACTION OF ATOMIC-HYDROGEN WITH METAL-SURFACES

The interaction of atomic hydrogen (deuterium) with clean and precover ed nickel and aluminum single-crystal surfaces has been investigated. The kinetics has been studied by thermal desorption spectroscopy and d irect monitoring of the reaction products with a multiplexed mass spec trometer. Dynamical studies in terms of the rotational and vibrational state distribution of the reaction products have been performed using REMPI spectroscopy. The initial sticking coefficient of atomic hydrog en is close to unity on nickel and about 0.6 on aluminum. Subsurface a bsorption can be observed on nickel but not on aluminum single-crystal surfaces. Atomic hydrogen (deuterium) interacts with pre-adsorbed deu terium (hydrogen) in form of Eley-Rideal reactions, hot-atom reactions and collision-induced desorption. The internal states of the reaction products (rotation, vibration) are highly excited.