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:
Jan. 19, 2016
Filed:
May. 20, 2011
Teiichiro Umezawa, Singapore, SG;
Takenori Kajiwara, Singapore, SG;
Tokichiro Sato, Singapore, SG;
WD Media (Singapore) Pte. Ltd., Singapore, SG;
Abstract
A perpendicular magnetic disk is provided. The disk includes, on a base and in the order from bottom, a first granular magnetic layer group including a plurality of magnetic layers each having a granular structure, a non-magnetic layer having Ru or a Ru alloy as a main component, a second granular magnetic layer group including a plurality of magnetic layers each having the granular structure, and an auxiliary recording layer having a CoCrPtRu alloy as a main component. Layers closer to a front surface among the plurality of magnetic layers included in the first granular magnetic layer group having an equal or smaller content of Pt. Layers closer to the front surface among the plurality of magnetic layers included in the second granular magnetic layer group having an equal or smaller content of Pt and having an equal or larger content of an oxide.