Method to improve remanence-squareness-thickness-product and coercivity profiles in magnetic media

摘要

A magnetic disk for information storage that includes a substrate and an information layer for containing information. The information layer includes a upper (e.g., recording) and lower (e.g., stabilizing) layers. The information layer has a remanence-squareness-thickness-product (“Mrt”) that varies radially between first and second disk radii. At least one of the following conditions is true: (i) the information layer has a coercivity that is at least substantially constant between the first and second disk radii; (ii) the lower magnetic layer has a magnetic anisotropy energy of no more than about 1.5×10⁶ erg/cm³; and (iii) the magnetic anisotropy energy of the upper magnetic layer is at least about 150% of the magnetic anisotropy energy of the lower magnetic layer.