Irradiation Effect of γ Rays on Diamond-Like Carbon Films

O59; Diamond-like carbon films, prepared by RF glow discharge on glasssubstrates, were irradiated by γ rays. The as-deposited and irradiated films were characterized by Raman spectroscopy, electrical resistivity, and infrared transmittance. It is shown that the irradiation of the γ rays can lead to the breaking of SP3C-H and SP2C-H bonds, slight increasing of SP3C-C bonds, and induced hydrogen recombination with H2 molecules, subsequently diffusing to the surface of the films. When the γ rays irradiation dose reached 10×104 Gy, the numbers of SP3C-H bonds was decreased by about 50%, the resistivity of irradiated DLC films was increased, and the diamond-like character of the films became more obvious. The structure of DLC films was modified when irradiated by γ rays. The irradiation mechanisms are briefly discussed.