Nanoindentation and nanowear of extremely thin protective layers of C-N and B-C-N

Carbon nitride (C-N) and boron and carbon nitride (B-C-N) films, 1 and 3 nm thick, were deposited on magnetic disks by means of a complex treatment method involving plasma irradiation and CN or BCN reactive sputtering in nitrogen and helium mixed gas using two targets of h-BN and graphite. The properties of these extremely thin coatings were evaluated by indentation using an atomic force microscope and nanowear tests using a lateral modulation friction force microscope. The extremely thin B-C-N coatings show highest indentation hardness and good wear resistance properties. It is proposed that this is due to their graduated composition and interfacial properties.