Evidence for oscillations in the C70 valence photoionization cross sections

Photoelectron spectra of molecular C70 were recorded in the photon energy range from 20 to 60 eV to investigate the photoionization cross section behavior of the outermost molecular orbitals. As in the case of C60, these photolines exhibit photon energy-dependent intensity oscillations, thus corroborating a quantum oscillation model based on the fullereneʹs unique shape. The photoelectron angular distribution parameter β measured during the same experiment shows, similarly to C60, no pronounced oscillations, rather rising continuously as the photon energy is increased, a fullerene-unspecific behavior also known from other carbon-containing molecules, such as CO.