The effect of hydrogen in carbon overcoats on the tribology of the head-disk interface

The effect of hydrogen in the carbon overcoat on the CSS durability of thin film media lubricated with perfluoropolyether (PFPE) is reported. A strain-gauge force transducer and optical surface analyzer (OSA) were employed to investigate the failure mechanism. The OSA provided in-situ monitoring of lubricant migration and modification as well as carbon wear. Durability improved with increasing hydrogen content over the range from 12 to 36 at% of H. The improvement is attributed to changes in lubricant bonding and mobility as a function of hydrogen content.