Patent ID: 7087325
Filing Date: 2006-08-08
Classification: C23C,G11B

Abstract:
1. 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 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.