Soft underlayer for heat assisted magnetic recording media

A recording medium, comprising:

• a magnetic recording layer;
• a soft underlayer disposed under the magnetic recording layer, the soft underlayer comprising:
• a first soft underlayer portion formed of a first soft underlayer material comprising a Cobalt-Iron (CoFe) material having a set of additives, the set of additives comprising W;
• and
• a second soft underlayer portion formed of a second soft underlayer material wherein the second underlayer material is different from the first underlayer material,
• wherein the first and second soft underlayer materials have Curie temperatures exceeding 300° C. and saturation magnetization values greater than 9 kGauss, and wherein the second soft underlayer material maintains an amorphous microstructure at a temperature greater than 450° C., wherein material composition ranges of the first and second soft underlayer materials comprise 20 to 90% Cobalt (Co), at most 60% Iron (Fe), at most 20% Nickel (Ni), at most 20% Zirconium (Zr), at most 15% Boron (B), at most 20% Tantalum (Ta), at most 10% Tungsten (W), and at most 10%_Molybdenum (Mo);
• and
• a spacer layer disposed between the first and second soft undeclayer portions, the spacer layer comprising material having inter-diffusion-resistant properties at temperatures greater than 1800° C., wherein the spacer layer is composed of one of Niobium (Nb), Vanadium (V), Mo, Osmium (Os), Carbon (C), Magnesium-Oxide (MgO), W, Rhenium (Re), Titanium Nitride (TiN), TiC, VN, MoC, TaN, TaC, Zr02, Yttrium Oxide (Y203), Silicon Dioxide (Si02), or Ta;
• an adhesion layer;
• and
• a heatsink layer configured to facilitate heat transfer for the recording medium, wherein the soft underlayer and heatsink layer are disposed over the adhesion layer and under the magnetic recording layer.