Abstract: A magnetic recording medium includes a nonmagnetic substrate and at least a magnetic layer, a protective layer, and a lubricating layer provided on the nonmagnetic substrate. The magnetic recording medium is characterized in that the lubricating layer is formed of a lubricating agent represented by general formulas (1), (2) or (3), in which substituents R1, R2, R3, and R4 in the lubricating agent represent organic groups, at least one of the substituents R1 and R2 at the end part of the lubricating agent and the substituents R3 and R4 contain a plurality of functional groups, and the shortest distance between the functional groups is a distance of three or more atoms, preferably five atoms. The magnetic recording medium may be used for a heat assisted recording method in which the temperature of the magnetic layer reaches 150° C. to 200° C.

Abstract: A magnetic recording medium includes a nonmagnetic substrate and at least a magnetic layer, a protective layer, and a lubricating layer provided on the nonmagnetic substrate. The magnetic recording medium is characterized in that the lubricating layer is formed of a lubricating agent represented by general formulas (1), (2) or (3), in which substituents R1, R2, R3, and R4 in the lubricating agent represent organic groups, at least one of the substituents R1 and R2 at the end part of the lubricating agent and the substituents R3 and R4 contain a plurality of functional groups, and the shortest distance between the functional groups is a distance of three or more atoms, preferably five atoms. The magnetic recording medium may be used for a heat assisted recording method in which the temperature of the magnetic layer reaches 150° C. to 200° C.

Abstract: A method of manufacturing a magnetic recording medium having a lubrication layer is disclosed. The method includes a step of simultaneously pressing a processing tape including a solvent against the edge face and the peripheral part of the data surface of the magnetic recording medium using a tape pressing device to wipe a liquid lubricant off while rotating the magnetic recording medium, after the liquid lubricant has been applied onto the protective layer. The non-magnetic substrate preferably has a thickness of 0.635 mm or less. The wiping with the processing tape is preferably performed after a heating process that follows the application of the liquid lubricant. The method makes the thickness of a lubrication layer of a magnetic recording medium uniform in a peripheral part thereof to allow a magnetic head to fly with stability.

Abstract: A carbon protective film of a magnetic recording medium includes a surface region having a high nitrogen concentration. The nitrogen-doped surface region enhances surface energy and improves wettability of the protective film with a liquid lubricant. The nitrogen is implanted by plasma treatment to produce a surface region in the protective film that includes from 6 to 20 at % of nitrogen in the surface region within 30 Å from the film surface. The treatment reduces the contact angle of the film surface with water to the range from of 10 to 30 degrees.