Digital magnetoresistive sensor based on the giant magnetoresistance effect
US5585986A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 15, 1995 |
| Grant date | Dec 17, 1996 |
| Priority date | — |
| Expiry date | May 15, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2495
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A magnetoresistive (MR) sensor based on the giant magnetoresistance (GMR) effect provides a digital output signal. The multilayer stack of alternating ferromagnetic layers and nonferromagnetic metal spacer layers in the GMR sensor has an essentially single crystalline structure so that each of the ferromagnetic layers exhibits uniaxial magnetic anisotropy, i.e. the magnetic moments of the ferromagnetic layers can lie only parallel or antiparallel to a single axis. Unlike GMR multilayers where all of the magnetic moments are affected simultaneously by the external magnetic field, in the present GMR sensor each ferromagnetic layer has its magnetic moment responsive to an external magnetic field strength that is different from the magnetic field strengths at which the magnetic moments of the other ferromagnetic layers are responsive. This allows each ferromagnetic layer to switch its magnetization direction from parallel to antiparallel, or vice versa, independently of the other ferromagnetic layers. This unique property of each ferromagnetic layer is accomplished by either selecting each ferromagnetic layer to have a different uniaxial magnetic anisotropy energy, such as by varying t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.