| 摘要 |
PURPOSE:To obtain a magnetic recording medium having superior electromagnetic transducing characteristics and durability by vapor-depositing Co or Co and Ni on a nonmagnetic substrate at a specified incident angle to form a magnetic thin film consisting of aggregated columnar crystals and by forming oxide layers on the surfaces of the crystals by a specified method. CONSTITUTION:A magnetic thin film consisting of aggregated columnar crystals of Co alone, Co-Ni having >=1.5 weight ratio of Co/Ni, or Co-Ni-Cr having 0.001-0.1 weight ratio of Cr/(Co or Co+Ni) is formed on a nonmagnetic substrate at >=20 deg. incident angle to the normal line of the principal surface of the substrate. The magnetic thin film is immersed in an aqueous soln. contg. an oxidizing agent such as nitric acid, H2Cr2O7 or H2O2 at 20-90 deg.C for about 0.1- 60min. The treated film is washed and dried by heating to form layers of Co, Ni or Cr oxide on the surfaces of the columnar crystals. The preferred atomic ratio of O/(Co or Co+Ni) in the magnetic layer is 0.05-0.5. Thus, a magnetic recording medium having superior corrosion resistance and high economical efficiency is obtd. |
