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. 20, 2004
Filed:
Aug. 15, 2002
Kenji Shimizu, Ichihara, JP;
Akira Sakawaki, Ichihara, JP;
Hui Yang, Ichihara, JP;
Hiro Mochizuki, Ichihara, JP;
Hiroshi Sakai, Ichihara, JP;
Takashi Hikosaka, Tokyo, JP;
Futoshi Nakamura, Ichikawa, JP;
Other;
Abstract
A magnetic recording medium that is capable of recording and reading back information at a higher density by improving the read/write characteristics and thermal stability, a method of manufacture therefor, and a magnetic read/write apparatus are provided. This magnetic recording medium, comprises an orientation control film that controls the orientation of a film provided directly thereabove, a perpendicular magnetic film, of which the axis of easy magnetization is generally oriented perpendicular to a non-magnetic substrate, and a protective film, that are provided on the non-magnetic substrate, wherein the perpendicular magnetic film is made of a material which contains Co, Cr, Pt and Cu, the Cr content being 16 at % to 24 at % and the Cu content being 0.1 at % to 4 at %, and a coercive force (Hc) of the perpendicular magnetic film being at least 3000 (Oe), negative nucleation field (−Hn) being 0 (Oe) to 2500 (Oe), and a ratio of residual magnetization (Mr) to saturation magnetization (Ms) being at least 0.85.