Novel hybrid magnetic overcoats: A prospective solution for low magnetic spacing.

A novel hybrid magnetic overcoat (Hy-MOC), consisting of a bilayer, suitable for ultrahigh density recording, has been proposed and investigated. The top layer is a thin layer of carbon (about 1 nm) employed mainly for the purpose of lubrication affinity. The bottom layer is a thin CoCrPt alloy layer with silicon oxide/nitride grain boundary (about 4 nm), which helps as an overcoat to prevent corrosion and also in reducing the magnetic spacing. Media prepared with such an overcoat showed a better recording performace and thermal stability than the media with a-C overcoat. The microstructure of the media with carbon overcoats and the magnetic overcoats obtained by transmission electron microscopy were comparable. Improved corrosion protection properties were also observed. These results indicate that Hy-MOC provides a possible solution for ultrathin overcoat system necessary for ultrahigh density media. [ABSTRACT FROM AUTHOR]