Strain sensors based on magnetostrictive GMR/TMR structures

Author

Löhndorf, M. ; Duenas, T.A. ; Ludwig, Alfred ; Rührig, M. ; Wecker, J. ; Bürgler, D. ; Grünberg, P. ; Quandt, Eckhard

Author_Institution

Center of Adv. Eur. Studies & Res., Bonn, Germany

Volume

38

Issue

5

fYear

2002

fDate

9/1/2002 12:00:00 AM

Firstpage

2826

Lastpage

2828

Abstract

This paper investigates magnetic layer structures suitable for devices measuring mechanical responses such as stress, strain and pressure. Results for giant magnetoresistance (GMR) multilayers and magnetic tunneling junctions (MTJs) intentionally prepared either with magnetostrictive Fe₅₀Co₅₀ materials or with amorphous Fe-based alloys serving as sensing (or "free") layers is discussed in view of possible applications. For MTJs prepared ex-situ with an amorphous FeCoSiB, free layer MR ratios of 33% are obtained leading to gauge factors GF=(ΔR/R)/Δε on the order of 300.

Keywords

giant magnetoresistance; magnetic multilayers; magnetic sensors; magnetoresistive devices; magnetostrictive devices; strain sensors; tunnelling; Fe₅₀Co₅₀; FeCoSiB; amorphous Fe-based alloys; amorphous FeCoSiB; free layer magnetoresistance ratios; gauge factors; giant magnetoresistance multilayers; magnetic layer structures; magnetic tunneling junctions; magnetostrictive Fe₅₀Co₅₀ materials; magnetostrictive GMR/TMR structures; mechanical responses; strain sensors; tunnel magnetoresistance; Amorphous magnetic materials; Amorphous materials; Capacitive sensors; Giant magnetoresistance; Magnetic field induced strain; Magnetic materials; Magnetic sensors; Magnetic tunneling; Magnetostriction; Strain measurement;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2002.802466

Filename

1042374