Electrochemical etching of magnetic recording layer

A perpendicular magnetic recording disk, comprising:

• A magnetic recording layer having a pattern of raised areas and recessed areas formed thereon, wherein the magnetic recording layer includes material within the recessed areas, and wherein the magnetic recording layer comprises a plurality of different cobalt-to-platinum (Co/Pt) ratios under the recessed areas being less than a cobalt-to-platinum ratio under the raised areas, wherein the plurality of Co/Pt ratios within each of the recessed areas decreases along a direction towards a center of each of the recessed areas, and wherein the plurality of Co/Pt ratios in each recessed area comprises at least a first Co/Pt ratio in a center region of the recessed area, a second Co/Pt ratio in a second region adjacent the center region and next to one of the raised areas, a third Co/Pt ratio in a third region between the second region and said one of the raised areas, and a fourth Co/Pt ratio in a fourth region between the third region and said one of the raised areas, wherein the first Co/Pt ratio is in a range between greater than zero and 0.5 or less, and wherein each of the first, second, third, and fourth Co/Pt ratios are different from each other.