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. 19, 2009
Filed:
Oct. 03, 2005
Reiko Arai, Kanagawa, JP;
Yoshiyuki Hirayama, Tokyo, JP;
Yuzuru Hosoe, Tokyo, JP;
Tomio Iwasaki, Ibaraki, JP;
Yoko Ogawa, Kanagawa, JP;
Ikuko Takekuma, Kanagawa, JP;
Reiko Arai, Kanagawa, JP;
Yoshiyuki Hirayama, Tokyo, JP;
Yuzuru Hosoe, Tokyo, JP;
Tomio Iwasaki, Ibaraki, JP;
Yoko Ogawa, Kanagawa, JP;
Ikuko Takekuma, Kanagawa, JP;
Hitachi Global Storage Technologies Netherlands B.V., Amsterdam, NL;
Abstract
Embodiments of the invention are directed to a medium which provides high media S/N and good corrosion resistance. According to one embodiment, in a perpendicular magnetic recording medium at least comprising a soft-magnetic underlayer, a seed layer, an intermediate layer, a magnetic recording layer and an overcoat layer which are stacked over a substrate in order, the magnetic recording layer has a granular structure which includes many columnar grains of CoCrPt alloy and a grain boundary layer containing an oxide, the seed layer is made of TaNi alloy or TaTi alloy and the intermediate layer is made of Ru or Ru alloy which contains 80 at. % Ru or more.