Patent ID: 7983003

Claim:
A perpendicular magnetic recording medium adapted to be mounted in a perpendicular magnetic recording type hard disk drive, said perpendicular magnetic recording medium comprising: a disk-shaped disk base, a soft magnetic layer formed on said disk base, said soft magnetic layer having magnetic particles with easy magnetization axes and hard magnetization axes with the easy magnetization axes of the soft magnetic layer being randomly oriented in-plane with the disk base; and a perpendicular magnetic recording layer formed on said soft magnetic layer, wherein, at respective portions of said soft magnetic layer, directional distribution of the easy magnetization axes of the magnetic particles included in each of said respective portions is isotropic with respect to respective directions in a main surface of said soft magnetic layer; and wherein a magnetic hysteresis loop in each of said respective portions of said soft magnetic layer is isotropic with respect to a magnetic field in radial directions and a magnetic field in a circumferential direction of said disk base.