Patent ID: 7545604

Claim:
A magnetic recording medium comprising an underlying film, a magnetic film and a protective film, which are formed in order on a substrate; wherein: said magnetic film is a cobalt-base alloy film containing chromium and having a plurality of magnetic layers stacked without interposition of any non-magnetic layer; said plurality of magnetic layers comprising first, second and third magnetic layers; said first magnetic layer is disposed between said underlying film and said second magnetic layer; said second magnetic layer being disposed between said first magnetic layer and said third magnetic layer; said third magnetic layer being disposed between said second magnetic layer and said protective film; the concentration of chromium contained in said first magnetic layer is lower than that of chromium contained in said second magnetic layer; said first magnetic layer has a thickness smaller than a thickness of said second magnetic layer; the magnetic layers which overlie said first magnetic layer further containing platinum and boron; and the concentration of chromium contained in said third magnetic layer is lower than the concentration of chromium contained in said second magnetic layer; wherein the sum of the concentration of cobalt and the concentration of platinum contained in said third magnetic layer is higher than the sum of the concentration of cobalt and the concentration of platinum contained in said second magnetic layer.