PRODUCTION OF MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To change the coercive force in a magnetic film by forming magnetic CoNi films contg. Ni to multi-layered structure dividedly to at least >=2 stages from the state of a low gaseous pressure to the state of the high gaseous pressure in a mixed atmosphere composed of N2 and Ar on a nonmagnetic substrate. CONSTITUTION:The CoNi film 19 contg N is formed by sputtering on the nonmagnetic substrate 21 in the state of the low gaseous pressure in the mixed atmosphere composed of N2 and Ar. The CoNi film 20 contg. N is then formed in the state of the high sputtering gaseous pressure. After the formation of the films 19, 20, the films are respectively annealed in a vacuum (300 deg.C and 30min). A magnetic recording medium which has the large coercive force on the front side of a film thickness and small coercive force on the substrate 21 side is thereby obtd. and the distribution of the coercive force can be matched with the magnetic field distribution generated from a magnetic head.