Photoemission study of oxygen adsorption on Rb C film surface

X-ray photoelectron spectroscopy XPS.and ultraviolet photoelectron spectroscopy UPS.have been used to investigate oxygen adsorption on the surface of Rb6C60 film at room temperature. The results show that the Rb6C60 surface is sensitive to oxygen adsorption. The absorbed oxygen changes the crystal structure of the film by pulling intercalated Rb atoms to the surface, forming Rb oxides. An initial rapid oxygen uptake is mainly related to the formation of rubidium peroxide Rb2O2.. There exists a strong reaction between C60 and Rb2O2, leading to the formation of rubidium carbonate Rb2CO3.. At high oxygen exposures, a slow further adsorption of oxygen is associated with the intensity increases of both Rb2CO3 and rubidium superoxide RbO2.species. q2000 Published by Elsevier Science B.V. All rights reserved.