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.

Date of Patent:
Dec. 19, 2006

Filed:

Mar. 17, 2003
Applicants:

Sadayuki Watanabe, Nagano, JP;

Yasushi Sakai, Nagano, JP;

Inventors:

Sadayuki Watanabe, Nagano, JP;

Yasushi Sakai, Nagano, JP;

Assignee:
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G11B 5/66 (2006.01);
U.S. Cl.
CPC ...
Abstract

A perpendicular magnetic recording medium has a magnetic recording layer with ferromagnetic crystalline grains and nonmagnetic and nonmetallic grain boundary region surrounding the grains. The surface of its underlayer, before forming the magnetic recording layer, is exposed to an Oor Natmosphere or an atmosphere of rare gas and Oor N, to attach the Oor Nas nucleation sites for promoting growth of the nonmagnetic and nonmetallic region. By forming the magnetic recording layer thereafter, both ferromagnetic crystalline grains and the nonmagnetic and nonmetallic grain boundary region are formed from the initial stage of the growth of the magnetic recording layer. Thus, a magnetic recording layer having excellent segregation structure can be formed.


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