Patent ID: 7087325

Claim:
A magnetic recording medium comprising ( 1 ) a non-magnetic substrate, ( 2 ) a non-magnetic undercoat film, ( 3 ) a magnetic film, and ( 4 ) a protective film, wherein the films are successively formed on the substrate by sputtering, wherein the magnetic film comprises Cr and Co and has a structure in which a number of magnetic grains are separated from one another by a grain boundary phase comprising the same constitutional elements that constitute the magnetic grains, and the intergrain distance in the grain boundary phase is 10 Å or more and wherein a ratio of a Cr concentration (c 2 ) of the grain boundary phase to a Cr concentration (c 1 ) of the magnetic grains, represented by c 2 /c 1 , is 1.4 or higher and the magnetic grains have a grain size of 60–200 Å, and wherein the magnetic film has a multi-layer structure in which magnetic unit layers and non-magnetic unit layers are alternately stacked and a magnetic unit layer is an innermost layer.