PERPENDICULAR MAGNETIC RECORDING DISK

摘要

A perpendicular magnetic recording disk is provided. The perpendicular magnetic recording disk includes an underlayer between a substrate and a perpendicular magnetic recording layer for inducing perpendicular orientation of the perpendicular magnetic recording layer, the perpendicular magnetic recording layer having a thickness in the range where the ratio of perpendicular coercivity Hc to maximum perpendicular coercivity Ho decreases with reduced thickness of the perpendicular magnetic recording layer.