Bimodal range distributions of low-energy carbon ions in tetrahedral amorphous carbon

Range and mixing distributions of carbon ions deposited onto tetrahedral amorphous carbon films at kinetic energies between 22 eV and 692 eV are measured utilizing high-resolution elastic recoil detection. These data are compared to respective calculations based on binary collision approximation as well as to classical molecular-dynamics simulations. The measured range profiles reveal asymmetric, bimodal structures which are not reproduced from theories. The measured mixing distributions approve the measured range distributions, in particular the observed differences between theory and experiment, which have to be considered in subplantation growth models.