Nano-size magnetic crystallite formation in Co-Cr thin films for perpendicular recording media

In order to understand the formation of nano-size magnetic domains in Co₇₆Cr₂₄ thin films for ultra-high density perpendicular magnetic recording, film thickness and sputtering gas pressures were investigated using a facing target sputtering (FTS) apparatus. Investigations of these films showed thy were composed of highly oriented hcp crystallites with lower Cr content (C_Cr) of isolated ferromagnetic areas uniformly distributed in the higher C _Cr host paramagnetic matrix. The diameter of the lower C_Cr areas in these films was between 3-5 nm. The perpendicular coercivity in the surface region was greater than 2400 Oe. Consequently, this film is considered to be a good candidate for perpendicular magnetic recording densities approaching 1000 Kfci (10 Gb/in²)