Patent ID: 8859118

Claim:
A perpendicular magnetic recording medium comprising: a base; a magnetic recording layer formed on the base and on which a signal is recorded; a ground layer provided below the magnetic recording layer; a non-magnetic granular layer disposed between the magnetic recording layer and the ground layer for controlling crystal orientation of the ground layer; and a soft magnetic layer provided below the ground layer, wherein the ground layer is configured to have three layers including, in an order from the base, a first ground layer that contains ruthenium, a second ground layer that contains ruthenium, the second ground layer having crystal particles finer than those of the first ground layer, and a third ground layer that contains a metal and no oxygen, and a gas pressure at film formation by sputtering for the second ground layer is the highest among those for the three layers, thereby providing a finer crystal structure in the second ground layer than in the first ground layer or third ground layer, wherein the non-magnetic granular layer has a chemical composition different from said third ground layer.