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:
Jul. 06, 2004
Filed:
Feb. 20, 2001
Kiwamu Tanahashi, Kokubunji, JP;
Atsushi Kikugawa, Higashimurayama, JP;
Yukio Honda, Fuchu, JP;
Masaaki Futamoto, Shiroyama, JP;
Akira Ishikawa, Kokubunji, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
A double layer perpendicular magnetic recording medium having a high medium S/N ratio at a recording density of 50 Gb/in or higher and a magnetic storage apparatus with a lower error rate and excellent reliability are obtained with a structure having soft magnetic underlayer , an intermediate layer and a perpendicular magnetic recording layer are sequentially formed on a substrate . The, intermediate layer is made to be a non-magnetic amorphous alloy, in which Ni is a main component and Zr is contained, and the soft magnetic underlayer is constituted of ferromagnetic nano-crystals precipitated by annealing.