Magnetoresistive sensor, magnetic head and magnetic disk apparatus
US6636391B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 20, 2001 |
| Grant date | Oct 21, 2003 |
| Priority date | — |
| Expiry date | Dec 27, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/3996
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetoresistive sensor employing a magnetoresistive sensor film of a GMR film or a TMR film and a magnetic flux guide to ensure high sensitivity and high stability. Magnetization of a magnetic flux guide and a first ferromagnetic layer, which is a free layer of a GMR sensor film or a TMR sensor film, are made to antiferromagnetically couple to each other via a nonmagnetic intermediate layer 21. Since net magnetic moment has become small in the area in which the magnetoresistive sensor film is arranged, and an angle of magnetization of the ferromagnetic layer rotated by magnetic field which has been guided by the magnetic flux guide enlarges, high sensitivity can be obtained. When a longitudinal biasing layer is provide for the magnetic flux guide, longitudinal biasing magnetic field is applied to the ferromagnetic layer as well which is antiferromagnetically coupled to the magnetic flux guide, thus being able to suppress Barkhausen noise of both the magnetic flux guide and the ferromagnetic layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.