In-stack single-domain stabilization of free layers for CIP and CPP spin-valve or tunnel-valve read heads
US6473279B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 4, 2001 |
| Grant date | Oct 29, 2002 |
| Priority date | — |
| Expiry date | Jan 27, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/3932
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An improved MR sensor has a ferromagnetic free layer whose magnetization is stabilized by an in-stack three layers combination, which including an auxiliary ferromagnetic layer proximate the ferromagnetic free layer, a non-magnetic spacer layer disposed between the ferromagnetic free layer and the auxiliary ferromagnetic layer, and a pinning layer adjacent to the auxiliary ferromagnetic layer. The pinning layer is directly exchange-coupled to the auxiliary ferromagnetic layer such that the magnetization of the auxiliary ferromagnetic layer is pinned. The non-magnetic spacer layer is made of a material, such as Ru, which induces an anti-ferromagnetic exchange coupling between the ferromagnetic free layer and the auxiliary ferromagnetic layer. The magnetization of the ferromagnetic free layer is stabilized in a single-domain state by the combination of the anti-ferromagnetic exchange-coupling and magnetostatic coupling between the ferromagnetic free layer and the auxiliary ferromagnetic layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.