Reaction of diamond thin films with atomic oxygen simulated as low-earth-orbit environment

Diamond thin films deposited using a hot filament chemical vapor deposition (CVD) technique have been explored to atomic oxygen simulated as low-earth-orbit environment to examine their erosion-resistance properties. X-ray photoelectron spectroscopy results suggest that the atomic oxygen reacts with the diamond surface and forms ether (C–O–C) and carbonyl (>C=O) configurations. After a 3 h exposure to the atomic oxygen beam with a flux of 2.6×1016 atoms/cm2s, the diamond films only show a small mass loss with a reaction efficiency of 8.28×10−26 cm3/atom. Such a small reaction efficiency suggests that the CVD diamond is highly erosion resistive to atomic oxygen and it can be used as a passivation material in space.