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:
Mar. 13, 2012
Filed:
Aug. 25, 2008
Gohei Kurokawa, Ichihara, JP;
Yuzo Sasaki, Ichihara, JP;
Tatsu Komatsuda, Ichihara, JP;
Atsushi Hashimoto, Chiba, JP;
Gohei Kurokawa, Ichihara, JP;
Yuzo Sasaki, Ichihara, JP;
Tatsu Komatsuda, Ichihara, JP;
Atsushi Hashimoto, Chiba, JP;
Showa Denko K.K., Tokyo, JP;
Abstract
A magnetic recording medium is provided which can record and reproduce high-density information by maintaining perpendicular orientation of a magnetic recording layer even with a decrease in thickness of nonmagnetic layers from an intermediate layer to a seed layer while decreasing the grain size of magnetic crystal grains to be consistent with an increase in recording density. A manufacturing method thereof and a magnetic recording and reproducing apparatus are also provided. The magnetic recording medium is a perpendicular magnetic recording medium including at least an underlying layer, an orientation control layer, a magnetic recording layer, and a protective layer formed on a nonmagnetic substrate. Here, the orientation control layer includes two or more layers of a seed layer and an intermediate layer from the substrate side. Materials of the seed layer and the intermediate layer are selected so that a contact angle of the intermediate layer material with respect to the seed layer material, which is amorphous, is in the range of 10 to 100 degrees.