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. 12, 2015
Filed:
Apr. 11, 2008
Yasushi Sakai, Nagano, JP;
Shunji Takenoiri, Yamanashi, JP;
Yasushi Sakai, Nagano, JP;
Shunji Takenoiri, Yamanashi, JP;
Fuji Electric Co., Ltd., Kawasaki-Shi, JP;
Abstract
A perpendicular magnetic recording medium includes a nonmagnetic substrate, and a soft magnetic layer, a first orientation control layer, a second orientation control layer, a nonmagnetic intermediate layer, a magnetic recording layer, and a protective layer layered sequentially on the nonmagnetic substrate. The first orientation control layer includes a thin film having a face-centered cubic (fcc) structure. The magnetic recording layer includes a thin film layer having ferromagnetic crystal grains and nonmagnetic grain boundaries surrounding the ferromagnetic crystal grains, the ferromagnetic crystal grains including a CoPt alloy having ferromagnetic properties, and the nonmagnetic grain boundaries including an oxide or a nitride. The nonmagnetic intermediate layer includes a thin film containing Ru. The second orientation control layer includes an alloy thin film having an element selected from among Ni and Fe and having the fcc structure, the second orientation control layer having a saturation magnetic flux density Bs of 1 T or lower.