Wear and hardness of carbon overcoats on magnetic recording sliders

Wear of diamond-like carbon (DLC) overcoats on magnetic recording sliders during contact start stop (CSS) testing is investigated by monitoring changes in the depths of ion-milled “trenches” on the air bearing surface. In addition, nano-indentation, scratch tests, and Raman spectroscopy were used to characterize the DLC films. The correlation between hardness and scratch resistance of DLC films on Si and Al203–TiC coupons as well as hardness and wear resistance of DLC overcoats on sliders during CSS testing is studied. DLC films that exhibit higher durability in scratch tests are found to also exhibit higher durability in CSS tests.