Wear corrosion properties of DLC films with different C 2 H 2 gas flows and CN layer of magnetic recording disks

Abstract

The wear corrosion properties of magnetic recording disks which correlate to hardness, lubricant bonded ratio and friction coefficient of ultra thin diamond like carbon films deposited with ion beam hydrogenated carbon and sputtering nitrogenated carbon respectively when, deposited on NiP/Al substrates were investigated. Results show that the ion beam deposition hydrogenated carbon (IBD–CH) films prepared at lower C₂H₂ gas flowrates or 1 nm sputter nitrogenated carbon (CN) deposited on 2 nm IBD–CH layers, exhibit a higher Raman intensity ratio I_d/I_g and G peak frequency. The hardness of diamond like carbon films increases with decreasing G peak frequency and intensity ratio I_dI/_g. The lubricant bonded ratio is dramatically increased from 12 to 38% when a 1·0 nm CN is deposited on a 2·0 nm IBD–CH layer. IBD–CH with 35 sccm C₂H₂ gas flowrate which shows the lowest weight loss, the lowest friction coefficient and the best wear corrosion resistance because of the optimised lubricant bonded ratio and the highest hardness.