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:
May. 02, 2017
Filed:
Nov. 09, 2015
Showa Denko K.k., Tokyo, JP;
Japan Atomic Energy Agency, Ibaraki, JP;
Kota Hasegawa, Chiba, JP;
Takahiro Ukai, Chiba, JP;
Eishin Yamakawa, Chiba, JP;
Shiro Entani, Ibaraki, JP;
Seiji Sakai, Ibaraki, JP;
SHOWA DENKO K.K., Tokyo, JP;
JAPAN ATOMIC ENERGY AGENCY, Ibaraki, JP;
Abstract
A perpendicular magnetic recording medium includes a perpendicular magnetic layer provided above a nonmagnetic substrate, and a protection layer provided on the perpendicular magnetic layer. The perpendicular magnetic layer has an hcp structure, and includes stacked layers having a (0002) crystal plane oriented parallel to a surface of the nonmagnetic substrate. An uppermost layer amongst the stacked layers includes polycrystal grains selected from a CoCr-base alloy, a CoPt-base alloy, a CoCrPt-base alloy, and a CoPtCr-base alloy. The protection layer makes contact with the uppermost layer of the perpendicular magnetic layer, and includes a single graphene layer or a graphene stack, and an amorphous carbon layer. The single graphene layer or the graphene stack is bonded in parallel to a (0002) crystal plane of the polycrystal grains.