Perpendicular magnetic recording medium and process for manufacture thereof

摘要

A perpendicular magnetic recording medium with SNR improved by reducing noise due to an auxiliary recording layer so that a higher recording density can be achieved. The perpendicular magnetic recording medium 100 includes a base, at least a magnetic recording layer 122 having a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a non-magnetic split layer 124 disposed on the magnetic recording layer 122 and containing Ru and oxygen; and an auxiliary recording layer 126 that is disposed on the split layer 124 and that is magnetically approximately continuous in an in-plane direction of a main surface of the base 110.

主权项

1. A perpendicular magnetic recording medium, comprising in the following order:
a base; a first magnetic recording layer having a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a second magnetic recording layer having a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a second split layer that is disposed on the second magnetic recording layer and that contains a Ru alloy as a main component and; a third magnetic recording layer having a granular structure in which a non-magnetic grain boundary portion is formed between crystal particles grown in a columnar shape; a first split layer that is disposed on the third magnetic recording layer and that contains a Ru alloy as a main component; and an auxiliary recording layer that contains Cr, that is disposed on the split layer and that is magnetically approximately continuous in an in-plane direction of a main surface of the base, wherein the first split layer is operative to reduce the migration of Cr from the auxiliary layer into the third magnetic layer upon anneal at 200 C or higher, as indicated by a reduced drop in coercivity (Oe) compared to an identical structure absent the first split layer.