A two-axis magnetometer using a single magnetic tunnel junction

Author

Kammerer, Jean-baptiste ; Hébrard, Luc ; Hehn, Michel ; Braun, Francis ; Alnot, Patrick ; Schuhl, Alain

Author_Institution

Lab. d´´Electronique et de Phys. des Syst.s Instrum.aux, Univ. Louis Pasteur, Strasbourg, France

Volume

4

Issue

3

fYear

2004

fDate

6/1/2004 12:00:00 AM

Firstpage

313

Lastpage

321

Abstract

Based on a qualitative study of the Stoner-Wohlfarth model, we point out that driving a magnetic tunnel junction (MTJ) with an alternative two-dimensional magnetic field allows to measure simultaneously two components of an external magnetic field. Only one single MTJ without a pinning layer is needed to measure both components of a magnetic field parallel to the junction plane. The response of the magnetometer does not depend on the resistance of the junction or the amplitude of its variations. A prototype has been manufactured and encouraging experimental results are presented. Sensitivities higher than 500 V/T and a noise level of 2 μT/√Hz are reported.

Keywords

magnetic sensors; magnetic tunnelling; magnetometers; MTJ; Stoner-Wohlfarth model; junction plane; magnetic field; magnetic sensors; magnetic tunnel junction; magnetometer; noise level; pinning layer; prototype; qualitative study; Electrical resistance measurement; Magnetic field measurement; Magnetic hysteresis; Magnetic moments; Magnetic sensors; Magnetic tunneling; Magnetometers; Manufacturing; Noise level; Prototypes; MTJ; Magnetic sensors; Stoner–Wohlfarth model; magnetic tunnel junction;

fLanguage

English

Journal_Title

Sensors Journal, IEEE

Publisher

ieee

ISSN

1530-437X

Type

jour

DOI

10.1109/JSEN.2004.824232

Filename

1294911