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, 2009
Filed:
Sep. 09, 2005
Tatsuya Hinoue, Kanagawa, JP;
Hidekazu Kashiwase, Kanagawa, JP;
Hiroyuki Suzuki, Kanagawa, JP;
Tomoo Yamamoto, Kanagawa, JP;
Tatsuya Hinoue, Kanagawa, JP;
Hidekazu Kashiwase, Kanagawa, JP;
Hiroyuki Suzuki, Kanagawa, JP;
Tomoo Yamamoto, Kanagawa, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
A longitudinal magnetic recording medium having a high medium S/N, with no problems in view of the overwrite characteristic, excellent in the bit error rate and sufficiently stable also to thermal fluctuations is provided. In one embodiment, a first underlayer, second underlayer, and a third underlayer are formed on a substrate and, further, a first magnetic layer, a spacer layer including Ru as a main ingredient, a second magnetic layer, and a third magnetic layer are formed in adjacent with each other in this order. The thickness of the second magnetic layer is made larger than the thickness of the third magnetic layer and the total for the concentrations of cobalt and platinum obtained in the second magnetic layer is not more than the total for the concentrations of cobalt and platinum contained in the third magnetic layer.