Deuteration of C₆₀ on a highly oriented pyrolytic graphite surface

Reactions on carbonaceous surfaces play an important role in processes such as H₂ formation in the interstellar medium. We have investigated the adsorption of C₆₀ molecules on a highly oriented pyrolytic graphite (HOPG) surface and then exposed them to a beam of deuterium atoms in order to investigate the formation of deuterated fullerenes. Scanning tunneling microscopy (STM) was used to probe the adsorbed molecules and their deuteration. Deuteration of C₆₀ films results in increased thermal stability of the film, relative to films of pristine C₆₀, along with an evolution towards higher deuterated species. The STM data provide confirmatory evidence for the formation of deuterated fullerene species.