Magnetic recording medium, magnetic recording medium manufacturing method, and magnetic disk

A magnetic disk in which a magnetic recording layer with a granular structure in which nonmagnetic grain boundary portions are formed between magnetic grains continuously grown in a columnar shape and a magnetically coupling layer adjacent to the magnetic recording layer and magnetically continuous in an in-plane direction of a nonmagnetic substrate are stacked in this order over the substrate, the magnetic disk wherein:

• at least the magnetically coupling layer out of the magnetically coupling layer and the magnetic recording layer comprises;
• a plurality of hard magnetic portions respectively formed at positions corresponding to recording regions, where magnetic signals are to be recorded, in the magnetic recording layer, and
• magnetic field shield portions formed between but without being disposed over the adjacent hard magnetic portions, respectively, wherein when magnetization curves are measured, the magnetization curve of each magnetic field shield portion has a slope greater than those of the hard magnetic portions in a region where an applied magnetic field is zero, and a residual magnetic polarization of each magnetic field shield portion is smaller than those of said hard magnetic portions.

A magnetic disk in which a magnetic recording layer with a granular structure in which nonmagnetic grain boundary portions are formed between magnetic grains continuously grown in a columnar shape and a magnetically coupling layer magnetically coupled to the magnetic grains in the magnetic recording layer are stacked in this order over a nonmagnetic disk-shaped substrate, the magnetic disk wherein:

• at least the magnetically coupling layer out of the magnetically coupling layer and the magnetic recording layer comprises hard magnetic portions and soft magnetic portions alternately adjacent to each other in a radial direction of said substrate magnetic field, said soft magnetic portions being formed between but without being disposed over or under the plurality of hard magnetic portions.