Fabrication and Properties of Double Layer Perpendicular Rigid Disks

Perpendicular magnetic recording is a promising method for the achievement of higher recording densities. The magnetic and crystal orientational properties of double-layer rigid disks for perpendicular magnetic recording were studied. The coercive force distribution in the Mo-Cu-Permalloy underlayer was investigated as a function of the sputtering gas pressure. At optimum Ar gas pressure, good uniformity of the coercive force distribution was obtained. Even in double-layer media, the crystal orientation of the Co-Cr layer is influenced by the characteristics and thickness of the treated surface layer of the substrate. Higher recording densities were obtained using a lower flying height and a thinner Co-Cr layer. A D
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recording density of 70 kFRPI was achieved for a 0.15-μm Co-Cr layer and a 0.3 μm thick singlepole type head at a flying height of 0.1 μm.