An investigation of photoassisted diffusion of oxygen in solid C60 films using resonant alpha-scattering

Abstract

The interaction of molecular oxygen with thin C60 films was investigated using the 3.04 MeV resonance in the 16O(α, α)16O elastic scattering reaction to measure the concentration profile of oxygen in the fullerene films. A thin (d ≍ 20 nm) layer containing oxygen was observed on the surface of C60 films (d ≍ 200 nm) exposed to ∼1 atm of O2 for 1 h in the absence of light. In contrast, oxygen was uniformly distributed throughout the entire film when samples were irradiated for 1 h with either a 488 nm Ar ion laser or Xe lamp in the presence of ∼1 atm of O2. This O2 uptake was found to be both power dependent and reversible.