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:
Sep. 21, 2010
Filed:
Oct. 25, 2005
Perpendicular magnetic recording medium having grain boundary layer containing ferromagnetic element
Yuzuru Hosoe, Tokyo, JP;
Atsushi Nakamura, Tokyo, JP;
Yoshio Takahashi, Tokyo, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
Embodiments of the invention ensure that a perpendicular magnetic recording medium having a granular magnetic recording layer made of CoCrPt alloy and Si oxide provides both high SNR and thermal stability. In one embodiment, a substantially amorphous grain boundary layer of a magnetic recording layer made of CoCrPt alloy and Si oxide contains a ferromagnetic element in a concentration from about 30 at. % to 50 at. % or more preferably from about 35 at. % to 47 at. %, so that intergrain exchange interaction takes place moderately. As a consequence, SNR of 18 dB or more and thermal stability of 3%/decade or less are achieved.