A new type of composite target is proposed for low Ar-gas-pressure (P Ar) deposition of CoPtCr-SiO2 granular perpendicular magnetic recording media. The proposed target is a Co-Pt-Cr-CoSi-enriched CoO sintered target, consisting of CoSi and CoO powders instead of SiO2 powder. Systematic analysis of film composition, microstructure, and magnetic properties of the granular films revealed that 1) the Co74 Pt 16 Cr10-8 mol% SiO2 granular film with O/Si ratio of 2 in the film is realized by using a CoO/CoSi ratio of 3 in the target for our sputtering system, and 2) media with S = 1, Hc = 5.0 kOe, and α = 2.9 was realized even under a low PAr of 0.6 Pa. This means that just the oxidization of Si into SiO2 is important for magnetic decoupling.
- information storage
- perpendicular magnetic recording
- thin film