C₆₀⁺ defect centers: Effect of rubidium intercalation into C₆₀ studied by EPR

The vanishing of C₆₀⁺ EPR centers during the intercalation of polycrystalline C₆₀ with rubidium is described as a two-stage process with inter- and intragrain penetration of rubidium into the C₆₀ sample. This process leads to quenching of C₆₀⁺ hole states through a recombination process. Two aspects of the results are discussed: 1. EPR assignment of the spectrum usually observed in pristine polycrystalline C₆₀ samples. 2. Similarity of the kinetics of alkali inter- and intragrain penetration into powdered C₆₀ to the kinetics of oxygen penetration through C₆₀ film, accompanied by the generation of C₆₀⁺ centers.