Anomalous properties of spin valves at elevated temperatures

Author

McMichael, R.D. ; Chen, P.J. ; Egelhoff, W.F., Jr.

Author_Institution

Nat. Inst. of Stand. & Technol., Gaithersburg, MD, USA

Volume

33

Issue

5

fYear

1997

fDate

9/1/1997 12:00:00 AM

Firstpage

3589

Lastpage

3591

Abstract

We present results of magnetoresistance measurements on a 50 nm NiO/2.7 nm Co/2.2 nm Cu/3.1 nm Co/2.5 nm Au spin valve performed in vacuum at temperatures up to 400°C. Values of ΔR/R, R, and coercivities were found to be reversible up to 200°C. Irreversible changes in transport properties observed at and above 250°C were concurrent with changes in the interlayer coupling. A striking result is that the coercivity of the NiO-coupled Co film remains large for temperatures at and above the Neel temperature of NiO. Evidence is presented for the existence of `coercivity transfer´ between the Co layers

Keywords

Neel temperature; antiferromagnetic materials; cobalt; coercive force; copper; ferromagnetic materials; giant magnetoresistance; gold; magnetic multilayers; nickel compounds; 2.2 nm; 2.5 nm; 2.7 nm; 3.1 nm; 400 to 250 C; 50 nm; Neel temperature; NiO; NiO-Co-Cu-Co-Au; NiO-coupled Co film; NiO/Co/Cu/Co/Au spin valve; anomalous properties; coercivities; coercivity transfer; elevated temperatures; interlayer coupling; irreversible changes; magnetoresistance; spin valves; temperature dependence; transport properties; vacuum; Annealing; Coercive force; Giant magnetoresistance; Gold; Magnetic field measurement; Magnetic properties; Spin valves; Temperature dependence; Temperature distribution; Thermal stability;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.619506

Filename

619506