Current-perpendicular-to-plane magnetoresistive sensor with free layer stabilized by in-stack orthogonal magnetic coupling
US7199984B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 16, 2004 |
| Grant date | Apr 3, 2007 |
| Priority date | — |
| Expiry date | May 25, 2025 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01F10/3295
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A magnetically-coupled structure has two ferromagnetic layers with their in-plane magnetization directions coupled orthogonally across an electrically-conducting spacer layer that induces the direct orthogonal magnetic coupling. The structure has application for in-stack biasing in a current-perpendicular-to-the-plane (CPP) magnetoresistive sensor. One of the ferromagnetic layers of the structure is a biasing ferromagnetic layer and the other ferromagnetic layer is the sensor free layer. An antiferromagnetic layer exchange-couples the biasing layer to fix its moment parallel to the moment of the sensor pinned layer. This allows a single annealing step to be used to set the magnetization direction of the biasing and pinned layers. The electrically-conducting spacer layer, the biasing layer and the antiferromagnetic layer that exchange-couples the biasing layer may all extend beyond the edges of the sensor stack.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.