Carbon overcoat and the process dependence on its microstructure and wear characteristics

Carbon films prepared by DC magnetron sputtering as an overcoat for rigid-disk thin film media are studied. The tribological or wear performance shows a strong dependence on the sputtering process. The microstructure of the carbon films was evaluated using transmission electron microscopy, scanning tunneling microscopy, and Raman scattering. The results show that the films with better wear performance have a more uniform grain size distribution with a higher percentage (2-3%) of SP bonded carbon atoms and have a homogeneous work function distribution as compared to the films with poor wear performance. Atomic resolution images show disorder of the carbon atoms on the surface; however, some hexagonal patterns extending over about 10 AA are visible.<
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