MAGNETIC RECORDING MEDIUM

• Main Authors: SEKI YOSHINORI, KOZU JUNICHI, SASAOKA YASUSHI
• Format: Patent
• Language: English
• Published: 30.07.1999
• Edition: 6
• Subjects: CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; PHYSICS; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION

PROBLEM TO BE SOLVED: To obtain sufficient durability and corrosion resistance in spite of a film thickness reduction and to substantially prevent the occurrence of a head crash in spite of an environment of a high temp., low humidity or high humidity by successively forming a ferromagnetic metallic thin film and a protective film of a carbonaceous thin-film having plural different oxidation temps. in an atmosphere contg. a specific ratio of oxygen on a nonmagnetic substrate. SOLUTION: A Cr ground surface layer (thickness 40 nm) and a Co alloy magnetic layer (thickness 50 nm) are formed at a substrate temp. of 200 deg.C by a sputtering method on an Al alloy disk substrate coated with NiP plating. This substrate is installed in a CVD apparatus and after the inside of this apparatus is evacuated, toluene is introduced therein and the amorphous carbon protective films are deposited at respective film thicknesses of 5, 10, 15 nm on the substrate under biasing. When the sample formed by applying a liquid lubricant thereon is subjected to measurement of a change in TG-MS mass number 44 in the atmosphere of 20 vol.% oxygen and the balance helium, two CO2 peaks by the oxidation of the carbon film are obtd. As a result, the formation of the protective films to the smaller thickness is made possible and the excellent CSS durability is obtd.