Patent ID: 7879468

Claim:
A magnetic recording medium, comprising: a substrate, a soft magnetic layer on the substrate, a crystal orientation control layer on the soft magnetic layer comprising a depressed portion in which at least a portion of the crystal orientation control layer is absent, and a magnetic recording layer on the crystal orientation layer wherein portions of the magnetic recording layer in the depressed portion of the crystal orientation layer have a non-granular structure and portions of the magnetic recording layer on portions of the crystal orientation control layer that are not depressed have a granular structure, wherein the depressed portion of the orientation control layer which is absent does not extend in depth to the surface of the soft magnetic layer, so that part of the orientation control layer remains in the depressed portion and wherein the surface of the crystal orientation control layer in portions that are not depressed and that are in contact with the magnetic recording layer comprises Ru or an Ru alloy having Ru crystals mutually separated by a grain boundary layer, the Ru crystals being mutually separated to an extent that the magnetic layer overlying the Ru or Ru alloy having Ru crystals has a granular structure.