MAGNETIC RECORDING MEDIUM AND ITS PRODUCTION

• Main Authors: ARAI HITOSHI, OKAYAMA HIROSHI, IZUMI TOSHIAKI
• Format: Patent
• Language: English
• Published: 09.01.1987
• Subjects: BASIC ELECTRIC ELEMENTS; 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; ELECTRICITY; INDUCTANCES; INFORMATION STORAGE; INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORDCARRIER AND TRANSDUCER; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; MAGNETS; METALLURGY; PHYSICS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TRANSFORMERS

PURPOSE:To enhance the corrosion resistance of the titled medium, to control the ageing deterioration and to obtain an excellent magnetic characteristic by allowing the relation between the segregation rate of Cr in the Co-Cr mag netic film provided on a substrate and the vertical anisotropic magnetic field to satisfy a specified value. CONSTITUTION:The magnetic this film contg. Co and Cr is formed on the sub strate. When the segregation rate of Cr of the magnetic thin film is designated as S(%) and the vertical anisotropic magnetic field as HK (KOe), the equations, Hk>=0.08S+3.2 and -20<=S<=0, must be satisfied. An arc-discharge ion-plating method along with the introduction of O2 is preferably used to form such a magnetic thin film. Furthermore, the content of Cr in the magnetic thin film is regulated to about 10-20wt% and the thickness is preferably controlled to 1,200-11,000Angstrom . A magnetic recording medium having such a magnetic thin film is provided with excellent corrosion resistance, less ageing deterioration and an excellent magnetic characteristic. Consequently, the medium is preferably used for a vertically magnetized tape, a magnetic disk, a flexible disk, etc.