Structure and mechanical properties of hydrogenated carbon films prepared by magnetron sputtering [for magnetic discs]

Hydrogenated thin carbon films have been prepared by DC magnetron sputtering in a hydrogen-containing argon HD-09. A monotonic decrease in friction buildup as well as an increase in abrasion resistance is observed for increasing hydrogen addition to the argon atmosphere, from 0 to 5%. Raman data show higher sp³ character, and an increase in hydrogen content in the film, as monitored with Fourier-transform infrared spectroscopy, is observed. Resistivity measurements also show a transition from conductor to insulator. For very high hydrogen content, the film becomes increasingly softer. These data are attributed to an initial increase in the sp³/sp² bonding ratio, followed by a loss of three-dimensional cross-linking, eventually leading to polymerization