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:
Jun. 06, 2017
Filed:
Dec. 04, 2014
Fuji Electric Co., Ltd., Kawasaki-shi, JP;
Hiroyasu Kataoka, Sendai, JP;
Hiroto Kikuchi, Sendai, JP;
Akira Furuta, Sendai, JP;
Shinji Uchida, Matsumoto, JP;
Takehito Shimatsu, Natori, JP;
FUJI ELECTRIC CO., LTD., Kawasaki-Shi, JP;
Abstract
A perpendicular magnetic recording medium includes at least a nonmagnetic substrate and a magnetic recording layer. The magnetic recording layer is constituted by a plurality of layers that includes at least a first magnetic recording layer and a second magnetic recording layer. The first magnetic recording layer has a granular structure that includes first magnetic crystal grains and first nonmagnetic crystal grain boundaries surrounding the first magnetic crystal grains. The first magnetic crystal grains include an ordered alloy, and the first nonmagnetic crystal grain boundaries are constituted by carbon. The second magnetic recording layer has a granular structure that includes second magnetic crystal grains and a second nonmagnetic crystal grain boundaries that surround the second magnetic crystal grains. The second magnetic crystal grains include an ordered alloy, and the second nonmagnetic crystal grain boundaries are constituted by a carbon-containing nonmagnetic material.