Adsorption of C[sub 60] on Ta(110): Photoemission and C [ital K]-edge studies

Photoelectron and near-edge spectroscopies are used to characterize a C[sub 60] film on a Ta(110) surface. Like similar studies of C[sub 60] on a variety of metal surfaces, the valence band, C 1[ital s] core level, and photoelectron-derived work-function measurements show that C[sub 60] molecular states are aligned with the Fermi level and the charge is transferred from the metal to the fullerene. The photoelectron and near-edge spectra of the C[sub 60] peaks closest to the Fermi level show significant changes in intensity identifying those [pi]-like states as interacting with the substrate. A careful examination of the C 1[ital s] and Ta 4[ital f] core levels suggests that some fraction of the fullerene overlayer decomposes on the clean metal surface leading to or resulting in, a thin layer of carbon between the assembled film and the metal substrate.