METHOD OF PRODUCING PERPENDICULAR MAGNETIC RECORDING MEDIUM

摘要

A method of producing a perpendicular magnetic recording medium with a magnetic recording layer formed from ferromagnetic crystal grains and oxide-including non-magnetic crystal grain boundaries and provided on a non-magnetic substrate. The method is initiated by forming the magnetic recording layer by a reactive sputtering method using rare gas containing 2% by volume to 10% by volume (both inclusively) of oxygen gas at an initial stage of film formation. The method continues by successively forming the magnetic recording layer by reactive sputtering while reducing the concentration of the oxygen gas. The method may further include forming an undercoat layer of Ru or a Ru-alloy under the magnetic recording layer. In this manner, a granular magnetic layer having high characteristic coercive force (Hc) can be formed, while reducing the amount of expensive Pt or Ru required.