Heat-assisted magnetic recording (HAMR) medium with improved corrosion resistance

A heat-assisted magnetic recording disk comprising:

• a substrate;
• a heat-sink layer on the substrate, the heat-sink layer comprising a single layer or multilayer selected from Ag, Al, Cu, Cr, Au, Ru, W and Mo;
• an amorphous underlayer directly on the heat-sink layer, the underlayer selected from the group consisting of a CoZrWMo alloy, a CoFeCrTa alloy and a CoCrTaZr alloy;
• an intermediate layer directly on the underlayer, the intermediate layer comprising a layer of a solid substitution crystalline alloy of the form (Mg(100-y)Niy)O, where y is less than 10 and greater than or equal to 0.5;
• and
• a magnetic recording layer comprising a chemically-ordered FePt alloy and a segregant on the intermediate layer.

A heat-assisted magnetic recording disk comprising:

• a substrate;
• a heat-sink layer consisting of Cr on the substrate;
• an intermediate layer directly on the heat-sink layer, the intermediate layer comprising a layer of a solid substitution crystalline alloy of the form (Mg(100-y)Niy)O, where y is less than 10 and greater than or equal to 0.5;
• and
• a magnetic recording layer comprising a chemically-ordered FePt alloy and a segregant directly on and in contact with the intermediate layer.