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:
Aug. 22, 2000
Filed:
Mar. 12, 1998
Marcos M Lederman, San Francisco, CA (US);
Read-Rite Corporation, Milpitas, CA (US);
Abstract
A current-pinned spin valve sensor includes a soft ferromagnetic free layer having a first thickness, a soft ferromagnetic pinned layer having a second thickness less than the first thickness, a copper layer sandwiched between the free and the pinned layer, and a current source coupled to the free layer, pinned layer, and copper layer to provide a biasing current that generates a magnetic field of sufficient strength to saturate the pinned layer. Preferably, the free layer and pinned layer selected from a group of materials consisting of essentially Permalloy, Cobalt, Iron-Cobalt, and soft Cobalt-based ferromagnetic alloys. Also preferably the free layer has an Mrt of at least 0.3 memu/cm.sup.2 and the pinned layer has a Mrt of at most 0.28 memu/cm.sup.2, and such that the ratio of the Mrt of the free layer to the Mrt of the pinned layer is in the range of 2-10. The biasing current through the sensor is preferably at least 4 mA. The biasing current creates a magnetic field which creates the proper magnetization in the pinned layer without the need for an antiferromagnetic (AFM) layer in contact with the pinned layer.