TRIBOLOGICAL BEHAVIOR OF AMORPHOUS-CARBON NITRIDE OVERCOATS FOR MAGNETIC THIN-FILM RIGID DISKS

Amorphous carbon nitride coatings of thickness of 5 and 30 nm were dep osited onto 65 and 95 mm magnetic thin-film rigid disks surfaces using single-cathode and dual-cathode magnetron sputtering systems containi ng nitrogen-argon plasmas. Under optimum deposition conditions, amorph ous carbon nitride coatings can be synthesized on ultrasmooth thin-fil m disks with no significant pinholes at thickness down To 5 nm, with h ardness 22-28 GPa (compared to 7-12 GPa for amorphous carbon), and r.m .s. roughness as low as 0.25 nm. These amorphous cai bon nitride coati ngs were shown to have better contact-start-stop performance and three -re-four times better pin-on-disk contact durability compared with amo rphous carbon overcoats under identical testing conditions. Amorphous carbon nitride appears to be a promising candidate overcoat material f or replacing amorphous carbon in. the next-generation magnetic thin-fi lm rigid disk systems.