Magnetic field sensor having nickel oxide and cobalt containing ferromagnetic layers
US6275033A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 26, 1998 |
| Grant date | Aug 14, 2001 |
| Priority date | — |
| Expiry date | Jan 26, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/1121
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A magnetic field sensor comprising a layered structure (3) E/F.sub.o /S/F, in which: E is an exchange-biasing layer, comprising nickel oxide; F.sub.o is a ferromagnetic layer with a fixed magnetization, comprising cobalt; S is a spacer layer; F.sub.f is a ferromagnetic layer with a free magnetization, whereby the material of the layer F.sub.f has a magnetostriction constant of at most 1.5.times.10.sup.-6 and a crystal anisotropy of at most 1.3 J/m.sup.3. Such a structure (3) demonstrates a relatively high magneto-resistance ratio (of the order of 15%), and yet a relatively low coercivity (of the order of 0.2 kA/m). Examples of suitable materials for use in the layer F.sub.f include Ni.sub.66 Fe.sub.16 Co.sub.18 and Ni.sub.72 Fe.sub.21 Co.sub.7.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.