Patent ID: 7713389

Claim:
A method for making a perpendicular magnetic recording disk having a substrate; an underlayer of magnetically permeable material on the substrate; a nonmagnetic intermediate layer comprising Ru on the underlayer; a perpendicular magnetic recording layer comprising a granular ferromagnetic Co alloy and one or more oxides of one or more of Si, Ta, Ti and Nb; and a discontinuous nucleation film comprising one or more oxides of an element selected from the group consisting of Ta, Nb, Ti, Si, Mn, and Hf between the intermediate layer and the recording layer, the method comprising: sputter depositing the Ru-containing intermediate layer at a sputtering pressure less than about 12 mTorr; sputter depositing the oxide-containing discontinuous nucleation film to an average thickness less than about 1.5 nm on the intermediate layer at a sputtering pressure greater than about 30 mTorr; and sputter depositing the perpendicular magnetic recording layer on regions of the discontinuous nucleation film and on the Ru-containing intermediate layer not covered by regions of the discontinuous nucleation film.