Perpendicular magnetic recording medium

摘要

An object is to provide a perpendicular magnetic recording medium including a ground layer that prevents corrosion, while achieving a primary object of promoting finer magnetic particles of a magnetic recording layer and isolation of these magnetic particles.;The structure of a perpendicular magnetic recording medium 100 according to the present invention includes, at least on a base 110: a magnetic recording layer 122 on which a signal is recorded; a ground layer 118 provided below the magnetic recording layer; a non-magnetic layer 116 for controlling crystal orientation of the ground layer; and a soft magnetic layer 114 provided below the non-magnetic layer. The ground layer 118 is configured to have three layers including, in an order from bottom, a first ground layer 118a and a second ground layer 118b that contain ruthenium, and a third ground layer 118c that contains a metal. A gas pressure at film formation by sputtering for the second ground layer 118b is the highest among those for the above three layers.

主权项

1. 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.