Abstract: An ionic lubricant includes a single lubricant compound having a perfluoropolyether main chain, wherein each end of the perfluoropolyether main chain is terminated by an end group, and at least one of the end groups includes an ionic bond and at least one functional group. The ionic perfluoropolyether lubricant has unique characteristics that allows its ultra-thin and uniform distribution over a protective overcoat layer of a magnetic recording medium, while at the same time providing its molecules with strong adhesion power to the protective overcoat layer of the magnetic recording medium compared to existing lubricants, so as to provide shorter magnetic spacing between the magnetic recording medium and the magnetic head, and enable longer operation hours for the magnetic recording medium.

Abstract: A method for making a magnetic recording medium, including providing a substrate, forming a magnetic layer on the substrate, applying filtered cathodic vacuum arc (FCVA) deposition to form a film on the magnetic layer, and performing nitridation on the film formed by the FCVA deposition.

Abstract: A perpendicular magnetic recording medium is disclosed in which crystal axis orientation dispersion, crystal grain diameter, and crystal grain diameter dispersion in a magnetic recording layer are reduced. The perpendicular magnetic recording medium has a structure having, stacked sequentially on a non-magnetic substrate, at least an amorphous underlayer, a lower orientation control layer made of Ru or Ru alloy of an hcp structure, an upper orientation control layer that is made of alloy containing an element selected from the group consisting of Co and Ni and an element selected from the group consisting of Cr, W, and Mo and that has an fcc or hcp structure, an intermediate layer, and a magnetic recording layer.

Abstract: An ionic lubricant includes a single lubricant compound having a perfluoropolyether main chain, wherein each end of the perfluoropolyether main chain is terminated by an end group, and at least one of the end groups includes an ionic bond and at least one functional group. The ionic perfluoropolyether lubricant has unique characteristics that allows its ultra-thin and uniform distribution over a protective overcoat layer of a magnetic recording medium, while at the same time providing its molecules with strong adhesion power to the protective overcoat layer of the magnetic recording medium compared to existing lubricants, so as to provide shorter magnetic spacing between the magnetic recording medium and the magnetic head, and enable longer operation hours for the magnetic recording medium.

Abstract: A method for manufacturing a protective film having a smaller thickness that none-the-less suppresses degradation of the protective film and maintains corrosion resistance is achieved. The method for manufacturing a carbon-containing protective film includes: (a) forming a carbon material film on a substrate by a plasma CVD method using a starting material gas containing a hydrocarbon gas; and (b) nitriding the carbon material film by using plasma generated from a nitrogen-containing starting material gas in a plasma CVD device having an anode and a cathode, to form the carbon-containing protective film. During nitriding, an anode potential may be equal to or greater than 20 V, an ion acceleration potential difference may be within a range of 20 V to 120 V, and a substrate current density may be within a range of 4×10?6 A/mm2 to 8×10?6 A/mm2.

Abstract: A method for making a magnetic recording medium, including providing a substrate, forming a magnetic layer on the substrate, applying filtered cathodic vacuum arc (FCVA) deposition to form a film on the magnetic layer, and performing nitridation on the film formed by the FCVA deposition.