Infrared and mechanical properties of the oxygen-doped non-hydrogenated diamond-like carbon film prepared by pulsed laser deposition

Abstract

The non-hydrogenated diamond-like carbon films were prepared by the femtosecond laser in the oxygen atmosphere, and the influence of the oxygen atmosphere on the microstructural, surface, infrared and mechanical properties of the oxygen-doped diamond-like carbon films were researched. The oxygen atmosphere was propitious to reduce the granules on the surfaces but increase the surface roughness of the diamond-like carbon DLC films. During the pulsed laser deposition, the carbon and oxygen atoms were inclined to form the CO bond, CO bond and CC hybridized bond, when the oxygen pressure was lower than 5 m Torr. Although the CO and CO bonds led one additional absorption band and two additional absorption peaks in the infrared spectra of the oxygen-doped diamond-like carbon films, their transmission in the medium infrared band increased. Nano-hardness of the DLC films was reduced when the oxygen pressure increased dominantly because the CC sp3 bonds with higher atomic binding energy were replaced the CO bonds with lower atomic binding energy.