Title :
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
fDate :
9/1/2002 12:00:00 AM
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;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2002.802466
