Increased sensitivity in local probe of magnetic properties
US6947319B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 30, 2004 |
| Grant date | Sep 20, 2005 |
| Priority date | — |
| Expiry date | Jun 30, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2029/5002
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
An apparatus, system, and method for probing magnetic permeability of a material located a distance from the apparatus comprises a first hard ferromagnetic layer, a second hard ferromagnetic layer, a first soft ferromagnetic layer, a second soft ferromagnetic layer, an intermediate layer disposed between the first hard ferromagnetic layer and the first soft ferromagnetic layer, an insulating layer between the first soft ferromagnetic layer and second soft ferromagnetic layer, and a spacer layer disposed between the second soft ferromagnetic layer and the second hard ferromagnetic layer, wherein the second soft ferromagnetic layer increases an on/off ratio of a magnetic field in the first soft ferromagnetic layer, wherein the on/off ratio is approximately 1.6, and wherein the second soft ferromagnetic layer pulls a magnetic field of the apparatus into the first soft ferromagnetic layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.