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:
Feb. 22, 2011
Filed:
May. 30, 2008
Hiroyuki Nakagawa, Kanagawa, JP;
Ryoko Araki, Tokyo, JP;
Naoto Ito, Kanagawa, JP;
Takayuki Ichihara, Tokyo, JP;
Hiroyuki Nakagawa, Kanagawa, JP;
Ryoko Araki, Tokyo, JP;
Naoto Ito, Kanagawa, JP;
Takayuki Ichihara, Tokyo, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
Embodiments of the present invention provide a perpendicular magnetic recording media having excellent resolution, signal to noise ratio (S/N), and a small adjacent track erasure. According to one embodiment, underlayers for controlling the orientation and segregation of a magnetic layer, a magnetic layer including an oxide and an alloy of magnetic materials mainly composed of Co, Cr, and Pt, and a ferromagnetic-metal layer which does not contain oxygen, are formed over a substrate. The magnetic layer has at least two layers including ferromagnetic grains and oxides, a first magnetic layer, which is the part of the magnetic layer closer to the substrate, has grain boundaries mainly composed of Cr oxide and at least one oxide selected from Si, Ti, Nb, and Ta, and grain boundaries of a second magnetic layer at the ferromagnetic-metal layer side includes at least one oxide selected from Si, Ti, Nb, and Ta in which Cr oxide is less than the first magnetic layer.