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:
Jul. 20, 2004
Filed:
Oct. 11, 2001
Richard Henry Dee, Boulder, CO (US);
Storage Technology Corporation, Louisville, CO (US);
Abstract
An apparatus and method in which a free layer of a spin valve sensor may be stabilized without using permanent magnets are provided. In one embodiment, the free layer is stabilized by a magnetic field applied to the free layer by a ferromagnetic layer pinned at 0 degrees. In an alternative embodiment, the magnetic field is applied by a synthetic antiferromagnetic layer. By eliminating the necessity of having permanent magnets, the drawbacks of these permanent magnets are also eliminated. The apparatus and method eliminate these drawbacks because, (a) layers used in the apparatus and method do not rely on any retention of magnetization; (b) the effect of an effective applied field is not sensitive to adjacent magnetic structures such as shields; (c) there is no permanent magnetism to be altered or lost in the apparatus and method; and (d) the ferromagnetic exchange interaction effect of the apparatus and method is adjustable.