Patent ID: 7041393

Claim:
A perpendicular magnetic recording medium with a perpendicular recording layer formed over a substrate through a soft magnetic underlayer, wherein a plurality of soft magnetic layers comprising nanocrystals and non-magnetic layers for physically separating the soft magnetic layers are seen on a transmission electron microscopy image observed by irradiating a section of the perpendicular magnetic recording medium with an electron beam in a direction of a normal to the section, wherein 110, 200 and 211 diffraction rings of a body-centered cubic structure are present in an electron diffraction pattern in a same view as for the transmission electron microscopy image, and wherein a magnetostatic interaction acts on and between adjacent soft magnetic layers through a corresponding non-magnetic layer, and wherein local magnetic closed loops, the magnetizations of which are locally directed in an opposite direction to one another, are formed between the adjacent soft magnetic layers, and each of the soft magnetic layers contains a plurality of crystal grains exchange-coupled to one another in a film plane direction and in a film thickness direction, and a coercive force of the soft magnetic layers is equal to or less than 0.10 Oe.