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. 22, 2009
Filed:
Oct. 09, 2007
Shunji Takenoiri, Nagano, JP;
Yasushi Sakai, Nagano, JP;
Shunji Takenoiri, Nagano, JP;
Yasushi Sakai, Nagano, JP;
Fuji Electric Device Technology Co., Ltd., Tokyo, JP;
Abstract
A perpendicular magnetic recording medium includes a nonmagnetic substrate; a first underlayer provided on the nonmagnetic substrate; a first nonmagnetic intermediate layer provided on the first underlayer; a second underlayer provided on the first nonmagnetic intermediate layer; a second nonmagnetic intermediate layer provided on the second underlayer; and a magnetic recording layer provided on the second nonmagnetic intermediate layer, wherein the first underlayer comprises a soft magnetic material which has a face-centered cubic structure and which includes at least Ni and Fe, and wherein the second underlayer comprises a soft magnetic material which has a face-centered cubic structure and which includes at least Co. The orientation dispersion is reduced and crystal grain diameters are smaller in the magnetic recording layer, and the film thickness of nonmagnetic intermediate layers can be decreased so that performance improvements such as reduced noise, increased S/N ratio, and improved write-ability are achieved.