Patent ID: 8320232

Claim:
A patterned perpendicular magnetic recording medium comprising: a substrate; a nonmagnetic underlayer on the substrate; a first ferromagnetic layer (MAG 1 ) having perpendicular magnetic anisotropy, the first ferromagnetic layer being an oxide-free alloy comprising cobalt, platinum and chromium; a first nonmagnetic interlayer (IL 1 ) on the first ferromagnetic layer, wherein said IL 1 comprises a material selected from Ru and a Ru-based alloy and has a thickness greater than or equal to 0.1 nm and less than or equal to 1.5 nm; a second nonmagnetic interlayer (IL 2 ) on said IL 1 , wherein said IL 2 comprises one or more oxides of an element selected from the group consisting of Ta, Nb, Ti, Si, Mn, and Hf and has a thickness greater than or equal to 0.2 nm and less than or equal to 1.0 nm; and a second ferromagnetic layer (MAG 2 ) on said IL 2 ; and wherein said MAG 1 , said IL 1 , said IL 2 and said MAG 2 are patterned into a plurality of discrete islands.