Patent ID: 8336193

Claim:
A process for making a magnetic recording medium having a magnetically partitioned magnetic recording pattern, which is characterized by comprising the following three steps (1), (2) and (3), conducted in this order: (1) a step of forming a magnetic layer on a non-magnetic substrate; (2) a step of removing surface layer portions of regions of the magnetic layer for magnetically partitioning the magnetic layer by ion milling; and (3) a step of exposing the regions of the magnetic layer, from which the surface layer portions have been removed in step (2), to a reactive plasma or a reactive ion, thereby modifying magnetic characteristics of said regions of magnetic layer, while magnetic characteristics of other regions of the magnetic layer are not modified, whereby a magnetic recording pattern is formed which is magnetically partitioned by said regions of magnetic layer having the modified characteristics, wherein exposure of the regions of magnetic layer to the reactive plasma or the reactive ion is carried out to an extent such that the magnetization of the regions of the magnetic layer having the modified characteristics is not larger than 75% of the magnetization of the other regions of the magnetic layer having the non-modified magnetic characteristics, or to an extent such that the coercive force of the regions of the magnetic layer having the modified magnetic characteristics is not larger than 50% of the coercive force of the other regions of the magnetic layer having the non-modified magnetic characteristics.