Patent ID: 6803117
Filing Date: 2004-10-12
Classification: G11B,Y10T

Abstract:
A magnetic recording medium comprising:a substrate; an underlayer provided above said substrate; an exchange layer structure including a ferromagnetic layer and a nonmagnetic coupling layer, said exchange layer structure being provided above said underlayer; and a magnetic recording layer provided above said exchange layer structure, wherein said ferromagnetic layer is CoCrPtB and said magnetic recording layer is composed of CoCrPtBCu, wherein said underlayer includes a first underlayer containing Cr as a main constituent thereof and contains at least one of Mo and W, and a second underlayer containing CrMo as a main constituent thereof, wherein said second underlayer is provided on said first underlayer, and wherein said first underlayer has a film thickness in the range of approximately 2 to 5 nm, the second underlayer has a film thickness in the range of approximately 2 to 6 nm, and the total film thickness of the first and second underlayers together is in the range of approximately 5 to 10 nm.