Granularity in overlying magnetic and non-magnetic layers

An apparatus comprising:

• a first granular layer overlying a granular layer stack, wherein the first granular layer includes hexagonal close-packed grains separated by voids;
• a second granular layer overlying the first granular layer, wherein the second granular layer includes hexagonal non-metal grains separated by a first segregant;
• a third granular layer overlying the second granular layer, wherein the third granular layer includes NaCl-structured grains separated by a second segregant;
• and
• a fourth granular layer overlying the third granular layer, wherein the fourth granular layer includes L10 grains separated by a third segregant.

An apparatus comprising:

• first metal grains separated by voids, wherein the first metal grains include a center to center distance;
• first non-metal grains separated by a first segregant, wherein the first non-metal grains are over the first metal grains and the first segregant is over the voids;
• a second non-metal grains separated by a second segregant, wherein the second non-metal grains are over the first non-metal grains and the second segregant is over the first segregant;
• and
• second metal grains separated by a third segregant, wherein
• the second metal grains are over the second non-metal grains,
• the third segregant is over the second segregant, and
• the second metal grains include the center to center distance.