MICRO-TRIBOLOGY OF CARBON-COATED THIN-FILM MEDIA WITH WELL-DEFINED SURFACE TEXTURE

Contact start/stop (CSS) performance is described for thin film media with well-defined surface texture on carbon overcoats. Using a photo-lithography technique, concentric circular hills with uniform height (ca. 20nm) are formed on the carbon overcoat to control apparent area of contact with a slider. This texturing process provides the medium with a flat magnetic layer independent of the texture profile, which would be suitable for high density recording. A decrease in apparent area of contact results in lower friction buildup during the CSS test, while it causes large wear of the carbon overcoat after the test. Take off velocity of the slider also becomes higher with a decrease in the apparent area of contact, which increases sliding distance prior to take off. Although the smaller apparent area of contact causes larger wear due to an increase in contact pressure and sliding distance between the medium and slider, it effectively limits an increase in the real area or contact, keeping friction low.