Magnetic layer of a magnetic recording disk, and related magnetic recording disks

A magnetic recording disk comprising:

• a substrate comprising a central opening, at least a first major surface, and an outermost perimeter, wherein the central opening defines an innermost perimeter of the magnetic recording disk, and wherein the outermost perimeter defines an outside diameter of the magnetic recording disk;
• a nucleation layer present on the first major surface;
• and
• a magnetic recording layer present on the nucleation layer, wherein the magnetic recording layer comprises:
• a plurality of three-dimensional segregant structures, wherein each three-dimensional segregant structure extends continuously from approximately the innermost perimeter of the magnetic recording disk to approximately the outside diameter of the magnetic recording disk, wherein each three-dimensional segregant structure is made of a first segregant material, wherein each three-dimensional segregant structure has a shape, and wherein the shapes of plurality of three-dimensional segregant structures are a repeating pattern across the magnetic recording layer, wherein each three-dimensional segregant structure has a first sidewall and a second sidewall, wherein the first sidewall and the second sidewall extend from the nucleation layer;
• and
• a plurality of magnetic grains between adjacent three-dimensional segregant structures, wherein the plurality of magnetic grains were sputtered onto the nucleation layer having the plurality of three-dimensional segregant structures, wherein a first plurality of the plurality of magnetic grains are directly adjacent to the first sidewall of each three-dimensional segregant structure and align in as-sputtered form with the first sidewall, and wherein a second plurality of the plurality of magnetic grains are directly adjacent to the second sidewall of each three-dimensional segregant structure and align in as-sputtered form with the second sidewall;
• and
• a second segregant material between adjacent magnetic grains that are part of the plurality of magnetic grains between adjacent three-dimensional segregant structures, wherein each of the plurality of three-dimensional segregant structures has a height that corresponds to a thickness of the corresponding three-dimensional segregant structure that overlies the nucleation layer in a direction perpendicular to the first major surface, wherein the second segregant material has a height that corresponds to a thickness of the second segregant material that overlies the nucleation layer in a direction perpendicular to the first major surface, and wherein the height of the second segregant material is greater than the height of each three-dimensional segregant structure.