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:
Dec. 25, 2012
Filed:
Jan. 13, 2009
Kaizhong Gao, Eden Praire, MN (US);
Qixu Chen, Milpitas, CA (US);
Chung-hee Chang, Fremont, CA (US);
Thomas Patrick Nolan, Fremont, CA (US);
Kaizhong Gao, Eden Praire, MN (US);
Qixu Chen, Milpitas, CA (US);
Chung-Hee Chang, Fremont, CA (US);
Thomas Patrick Nolan, Fremont, CA (US);
Seagate Technology LLC, Cupertino, CA (US);
Abstract
A media for perpendicular recording and a method of creating the media is provided. The media includes a hard recording layer and a soft underlayer (SUL). The SUL is composed of at least two anti-ferromagnetically coupled (AFC) sub-underlayers. The sub-underlayers respond to a magnetic field established during dynamic reversal with respective magnetic fields. The sub-underlayers are formed and disposed to differ in one or more magnetic moment, anisotropy, and thickness, so that their respective magnetic fields constructively interfere in one or more points in the hard recording layer, thereby reducing a total SUL magnetic field response to the dynamic reversal field approximately to zero at one or more points in the hard recording layer, which reduces side track erasure.