MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To obtain a medium provided with a highly corrosion resistant thin magnetic metallic film layer having a high recording density by forming a magnetic layer of a cobalt-nickel alloy contg. niobium and interposing an intermediate protective layer consisting of niobium between said magnetic layer and protective lubricating layer. CONSTITUTION:A disk-shaped Al-Mg alloy is used as a substrate 1 and is finished to a less waved disk having decreased surface deflection by machining and grinding. An Ni-P alloy layer is formed by electroless plating to a prescribed thickness as a nonmagnetic substrate layer 2 on the surface thereof. The surface of said layer is finished by polishing to a specular surface. Cr is then thinly formed as a nonmagnetic metallic underlying layer 3 and the magnetic layer 4 having a prescribed thickness is formed thereon by sputtering a Co alloy contg. Ni and Nb. Nb is further sputtered thereon to form the intermediate protective layer 5. The protective lubricating layer 6 consisting of C is formed thereon by using a high-purity carbon graphite target and sputtering said target. The magnetic recording medium is thus manufactured.