| 摘要 |
PROBLEM TO BE SOLVED: To provide a perpendicular magnetic recording medium which increases recording density by reducing the surface roughness of a magnetic recording medium while securing a satisfactory SNR, so as to achieve further reduction in flying height of a magnetic head. SOLUTION: The perpendicular magnetic recording medium comprises, over a substrate, a magnetic recording layer, an underlayer made of Ru or an Ru compound and provided below the magnetic recording layer, a pre-underlayer made of a nonmagnetic crystalline material, and a soft magnetic layer provided below the pre-underlayer. When a difference between the highest point and the lowest point of unevenness of the interface between the soft magnetic layer and the pre-underlayer, obtained by a cross-sectional TEM image, is defined as an interface roughness (nm), and the distance between the soft magnetic layer and the magnetic recording layer, excluding the soft magnetic layer and the magnetic recording layer, is defined as a SUL-MAG distance (nm), interface roughness (nm)≤0.4 (nm) and interface roughness×SUL-MAG distance (nm)≤12 (nm) are satisfied. COPYRIGHT: (C)2011,JPO&INPIT |
