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:
Apr. 29, 2014
Filed:
Mar. 20, 2007
Ikuko Takekuma, Kanagawa, JP;
Hiroyuki Nakagawa, Kanagawa, JP;
Hiroaki Nemoto, Kanagawa, JP;
Yoshiyuki Hirayama, Tokyo, JP;
Ikuko Takekuma, Kanagawa, JP;
Hiroyuki Nakagawa, Kanagawa, JP;
Hiroaki Nemoto, Kanagawa, JP;
Yoshiyuki Hirayama, Tokyo, JP;
HGST Netherlands B.V., Amsterdam, NL;
Abstract
According to embodiments of the present invention, a shielded pole writer and a perpendicular magnetic recording medium suitable thereto are combined to provide high medium SNR and excellent OW characteristic simultaneously. A perpendicular magnetic recording medium of a magnetic storage apparatus mounting a shielded pole writer, including a perpendicular magnetic recording medium having a recording layer of a three layered structure is used. A first recording layer has a granular structure consisting of grain boundaries containing an oxide and columnar grains comprising a CoCrPt alloy, in which a second recording layer and a third recording layer formed thereabove comprise Co as a main ingredient, contain Cr and do not contain an oxide, and the Cr concentration in the second recording layer is lower than the Cr concentration in the third recording layer.