Composite perpendicular recording medium consisting of CoCrPt with large Hk⊥ and CoCr with positive inter-particle interaction

A composite perpendicular medium with a (Co72Cr28)78Pt22 layer over a Cr-rich Co72Cr28 layer was fabricated to realize a high S/N in the high-recording density region by taking advantage of the strong particle interaction in the Co-rich CoCr layer. Characterization of the composite medium with a merged Mr head yielded an S/N of 24.0 dB at 200 kFCI and a D50 of 205 kFCI, with a 50-nm magnetic spacing.