Patent ID: 8398870
Filing Date: 2013-03-19
Classification: G11B

Abstract:
1. A method for manufacturing a perpendicular magnetic recording medium which is a method for manufacturing a perpendicular magnetic recording medium by forming a laminated structure containing a soft magnetic layer and a perpendicular magnetic layer on top of a non-magnetic substrate, the method comprising: a polishing step in which the surface of a non-magnetic substrate is smoothed before forming the laminated structure on top of the non-magnetic substrate, wherein a polishing liquid used in the polishing step contains abrasive grains consisting essentially of diamond particles within a range from 0.001 to 0.05% by mass and also contains a polishing accelerator within a range from 10 to 100 times the mass amount of diamond particles, and the polishing accelerator is an organic polymer material containing a sulfonic group or a carboxylic group and having an average molecular weight of 4,000 to 10,000.