Perpendicular magnetic recording disk

摘要

[Problem] A perpendicular magnetic disk with an improved SNR and increased recording density by further advancing microfabrication and uniformalization of particle diameters and improving crystal orientation regarding a preliminary ground layer made of a Ni-base alloy is provided.;[Solution] The perpendicular magnetic disk includes: on a base 110, a first Ni alloy layer 142 and a second Ni alloy layer 144; a ground layer 150 having Ru as a main component; and a perpendicular magnetic recording layer 160 containing a CoPt-base alloy and an oxide in this order, the first Ni alloy layer 142 and the second Ni alloy layer 144 including at least one element that takes a bcc crystal structure as a simple substance, and the second Ni alloy layer 144 further including an oxide.

主权项

1. A perpendicular magnetic disk comprising:
a substrate; on the substrate, a soft magnetic layer; a first Ni alloy layer and a second Ni alloy layer; a ground layer having Ru as a main component; and a perpendicular magnetic recording layer containing a CoPt-base alloy and an oxide in this order, both the first Ni alloy layer and the second Ni alloy layer including at least one element that takes a bcc crystal structure as a simple substance, and the second Ni alloy layer further including a metal oxide, wherein the element taking the bcc crystal structure included in the first Ni alloy layer has a content equal to or larger than 3 atomic percent and equal to or smaller than 10 atomic percent, wherein the second Ni alloy layer has a film thickness equal to or larger than 1 nm and equal to or smaller than 5 nm, and wherein said first Ni alloy layer has a thickness of 7 nm and is greater in thickness than the second Ni alloy layer, being between 1.4 and 7 times thicker than the second Ni-alloy layer.