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:
Dec. 24, 2013
Filed:
Dec. 21, 2012
Hgst Netherlands B.v., Amsterdam, NL;
Masayoshi Shimizu, Chigasaki, JP;
Hiroyuki Nakagawa, Yokohama, JP;
Shun Tonooka, Odawara, JP;
Yoshinori Honda, Hiratsuka, JP;
HGST Netherlands B.V., Amsterdam, NL;
Abstract
In one general embodiment, a perpendicular magnetic recording medium includes a ferromagnetic granular layer with perpendicular magnetic anisotropy and having a granular structure; and a cap layer above said granular layer, the cap layer being a ferromagnetic continuous layer with perpendicular magnetic anisotropy, wherein, near a first side of said granular layer nearest the cap layer. Surfaces of the ferromagnetic grains of said granular layer facing the cap layer each have a domed shape defining undulations along the first side. Indentations in said ferromagnetic grains are filled by the oxide of the grain boundary in a vicinity of the first side of said granular layer. Undulations on a granular layer side of said cap layer are flatter than the undulations of the ferromagnetic grains on the first side of said granular layer.