The surface radicals of diamond Original Research Article

The formation of diamond surface radicals and their destruction has been investigated using electron paramagnetic resonance (EPR) spectroscopy. The similarity in behavior of diamond paramagnetic susceptibility and thermodesorption with heat-treatment temperature indicates that the formation of paramagnetic centers is a result of the desorption of oxy-functional groups in connection with the simultaneous annealing of these centers. The destruction of the radicals associated with the chemisorption of oxygen and the value of the g-factor indicate that the observed paramagnetic centers are in fact carbon σ-radicals. The data obtained are important in the context of the diamond powder solid-phase caking process.