The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 10, 2015
Filed:
May. 31, 2011
Kazuaki Sakamoto, Singapore, SG;
Kazuaki Sakamoto, Singapore, SG;
WD Media (Singapore) Pte. Ltd., Singapore, SG;
Abstract
[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, a first Ni alloy layerand a second Ni alloy layer; a ground layerhaving Ru as a main component; and a perpendicular magnetic recording layercontaining a CoPt-base alloy and an oxide in this order, the first Ni alloy layerand the second Ni alloy layerincluding at least one element that takes a bcc crystal structure as a simple substance, and the second Ni alloy layerfurther including an oxide.