Magnetic layering for bit-patterned media

A magnetic recording medium comprising:

• a non-magnetic substrate;
• a soft magnetic under-layer overlaying the substrate;
• and
• a magnetic recording layer comprising a plurality of bit-patterned magnetic islands, each island of the plurality of islands overlaying the soft magnetic under-layer and each comprising a first magnetic sub-layer adjacent a second magnetic sub-layer, the recording layer further comprising a continuous third sub-layer extending between to connect each of the plurality of islands;
• wherein the second sub-layer of each of the magnetic islands overlays the corresponding first sub-layer of each of the magnetic islands, and the first sub-layer of each of the magnetic islands overlays the continuous third sub-layer of the recording layer and has a magnetic anisotropy that is greater than a magnetic anisotropy of the second sub-layer of each of the magnetic islands;
• and
• the continuous third sub-layer overlays the soft magnetic under-layer to form an interlayer having a structure to help to produce the greater magnetic anisotropy of first magnetic sub-layer.

A magnetic recording medium comprising:

• a non-magnetic substrate;
• a soft magnetic under-layer overlaying the substrate;
• and
• a magnetic recording layer comprising a plurality of bit-patterned magnetic islands, each of the plurality of islands overlaying the soft magnetic under-layer and each island comprising a first magnetic sub-layer overlaid by a second magnetic sub-layer, the recording layer further comprising a continuous interlayer, extending between the first sub-layer of each of the magnetic islands, and a continuous third magnetic sub-layer, extending to connect each of the plurality of islands and overlaying the second sub-layer of each of the magnetic islands;
• wherein the first sub-layer of each of the magnetic islands of the magnetic recording layer has a magnetic anisotropy that is greater than a magnetic anisotropy of the second sub-layer of each of the magnetic islands;
• and
• the magnetic anisotropy of the second sub-layer of each of the magnetic islands of the magnetic recording layer varies across a thickness of the second sub-layer and is always greater than a magnetic anisotropy of the continuous third sub-layer of the magnetic recording layer.