Magnetoimpedance in narrow NiFe/Au/NiFe multilayer film systems

Author

de Cos, D. ; Panina, L.V. ; Fry, N. ; Orue, I. ; García-Arribas, A. ; Barandiarán, J.M.

Author_Institution

Dept. de Electr. y Electron., Pais Vasco Univ., Bilbao, Spain

Volume

41

Issue

10

fYear

2005

Firstpage

3697

Lastpage

3699

Abstract

Magnetoimpedance (MI) in RF sputtered magnetic/metallic multilayers of composition NiFe/Au/NiFe has been investigated with the purpose of clarifying the effect of in-plane size. The film width was varied between 20 μm and 200 μm, the length was 2 or 5 mm and the layer thickness was 0.5 μm. The films of 50 μm wide demonstrated the highest MI ratio of more than 140% for frequencies of 200-400 MHz. We believe this is one of the best obtained results regarding the film dimensions and sensitivity. However, when the width is further decreased, the MI ratio drops considerably due to flux leakage through the inner conductor. This effect was analyzed within a 2-D model of a three-layer symmetrical film system, having magnetically open-loop structure, giving a reasonable agreement with the experimental results in 50 and 20 μm wide films.

Keywords

enhanced magnetoresistance; gold; iron alloys; magnetic multilayers; magnetic thin films; nickel alloys; 0.5 micron; 20 micron; 200 to 400 MHz; 50 micron; NiFe-Au-NiFe; enhanced magnetoresistance; flux leakage; magnetic multilayers; magnetic open-loop structure; magnetic thin films; magnetoimpedance sensors; multilayer film systems; three-layer symmetrical film system; transverse anisotropy; Amorphous magnetic materials; Frequency; Gold; Impedance; Magnetic anisotropy; Magnetic films; Magnetic flux leakage; Magnetic multilayers; Perpendicular magnetic anisotropy; Soft magnetic materials; Flux leakage; head efficiency; magnetoimpedance sensors; thin films; transverse anisotropy;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2005.854812

Filename

1519415