Energy partition in collisions of C60+ ions with diamond (111) and graphite (0001) surfaces

Abstract

Velocity distributions and fragmentation of C₆₀ molecules after collision with type IAa diamond (111) and graphite (0001) surfaces are studied for primary energies up to 500 eV at a scattering angle of 140° using time‐of‐flight mass spectrometry. The absolute scattering yield is much lower for diamond due to polishing induced surface corrugation. However, the final velocity distribution of C₆₀⁺ and its rate of metastable fragmentation after collision are similar for scattering off the two targets, and is interpreted by their similar lateral atomic structure. At a particular impact energy, the final internal energy of C₆₀⁺, as monitored by the rate of metastable fragmentation, increases with final kinetic energy, but the energy transferred to the target decreases. These results are understood when considering the collision as a two‐step mechanism, in which the impact energy is transformed into thermal and deformational energy of the target and C₆₀. This latter energy is subsequently transformed to final kinetic and further thermal energy.