Abutted exchange bias design for sensor stabilization
US7283337B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 4, 2005 |
| Grant date | Oct 16, 2007 |
| Priority date | — |
| Expiry date | Apr 29, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B5/3932
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A hard bias (HB) structure for biasing a free layer in a MR sensor within a magnetic read head is comprised of a main biasing layer with a large negative magnetostriction (λS) value. Compressive stress in the device after lapping induces a strong in-plane anisotropy that effectively provides a longitudinal bias to stabilize the sensor. The main biasing layer is formed between two FM layers, and at least one AFM layer is disposed above the upper FM layer or below the lower FM layer. Additionally, there may be a Ta/Ni or Ta/NiFe seed layer as the bottom layer in the HB structure. Compared with a conventional abutted junction exchange bias design, the HB structure described herein results in higher output amplitude under similar asymmetry sigma and significantly decreases sidelobe occurrence. Furthermore, smaller MRWu with a similar track width is achieved since the main biasing layer acts as a side shield.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.