Synthetic free layer for CPP GMR
US6953601B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 2002 |
| Grant date | Oct 11, 2005 |
| Priority date | — |
| Expiry date | Nov 25, 2023 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B2005/3996
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Reduction of the free layer thickness in GMR devices is desirable in order to meet higher signal requirements, besides improving the GMR ratio itself. However, thinning of the free layer reduces the GMR ratio and leads to poor thermal stability. This problem has been overcome by making AP2 from an inverse GMR material and by changing the free layer from a single uniform layer to a ferromagnetic layer AFM (antiferromagnetically) coupled to a layer of inverse GMR material. Examples of alloys that may be used for the inverse GMR materials include FeCr, NiFeCr, NiCr, CoCr, CoFeCr, and CoFeV. Additionally, the ruthenium layer normally used to effect antiferromagnetic coupling can be replaced by a layer of chromium. A process to manufacture the structure is also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.