PRODUCTION OF MAGNETIC RECORDING MEDIUM

PURPOSE:To obtain high coercive force by forming a prescribed thin alloy film on a substrate provided with a thin Cr underlying film of a prescribed thickness in the state of impressing a potential positive with respect to a substrate on an intermediate electrode. CONSTITUTION:The substrate 3 formed with the Cr underlying layer is mounted to a holder 2 and is executed sputtering in the presence of a rare gas by using a target 1 consisting of a Co-Cr-Ta alloy. The sputtering is executed in the state of impressing the potential (50 to 500V) positive with respect to the substrate 3 on the intermediate electrode 4 at this time to form the thin magnetic film consisting of Co, Cr and Ta on the substrate 3. The film thickness of the Cr underlying layer is 10 to 1,200Angstrom , more preferably 50 to 100Angstrom , further preferably 100 to 500Angstrom . The coercive force of the magnetic layer degrades drastically if the film thickness is