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:
Feb. 26, 2013
Filed:
Aug. 21, 2009
Matthew J. Carey, San Jose, CA (US);
Jeffrey R. Childress, San Jose, CA (US);
Stefan Maat, San Jose, CA (US);
Matthew J. Carey, San Jose, CA (US);
Jeffrey R. Childress, San Jose, CA (US);
Stefan Maat, San Jose, CA (US);
HGST Netherlands B.V., Amsterdam, NL;
Abstract
A tunneling magnetoresistance (TMR) device, like a TMR read head for a magnetic recording disk drive, has low magnetic damping, and thus low mag-noise, as a result of the addition of a ferromagnetic backing layer to the ferromagnetic free layer. The backing layer is a material with a low Gilbert damping constant or parameter α, the well-known dimensionless coefficient in the Landau-Lifshitz-Gilbert equation. The backing layer may have a thickness such that it contributes up to two-thirds of the total moment/area of the combined free layer and backing layer. The backing layer may be formed of a material having a composition selected from (CoFe)X, (CoMn)Xand (CoFeMn)X, where X is selected from Ge, Al and Si, and (CoFe)Al, where y is in a range that results in a low damping constant for the material.