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:
Jul. 01, 2004
B. Ramamurthy Acharya, Cupertino, CA (US);
Gunn Choe, San Jose, CA (US);
B. Ramamurthy Acharya, Cupertino, CA (US);
Gunn Choe, San Jose, CA (US);
Seagate Technology LLC, Scotts Valley, CA (US);
Abstract
A magnetic disk for information storage that includes a substrate and an information layer for containing information. The information layer includes a upper (e.g., recording) and lower (e.g., stabilizing) layers. The information layer has a remanence-squareness-thickness-product ('Mrt') that varies radially between first and second disk radii. At least one of the following conditions is true: (i) the information layer has a coercivity that is at least substantially constant between the first and second disk radii; (ii) the lower magnetic layer has a magnetic anisotropy energy of no more than about 1.5×10erg/cm; and (iii) the magnetic anisotropy energy of the upper magnetic layer is at least about 150% of the magnetic anisotropy energy of the lower magnetic layer.