Magnetic properties of nanometric Fe wires obtained by multiple extrusions

Author

Wacquant, F. ; Denolly, S. ; Giguere, A. ; Noziéres, J.P. ; Givord, D. ; Mazauric, V.

Author_Institution

Lab. Louis Neel, CNRS, Grenoble, France

Volume

35

Issue

5

fYear

1999

fDate

9/1/1999 12:00:00 AM

Firstpage

3484

Lastpage

3486

Abstract

A method for producing arrays of nanometric wires is briefly described. The method consists of extruding a compact containing parallel iron wires spaced in a copper matrix until the wires become extremely small (10 nm at the ultimate stage). Coercive forces up to 0.04 T are found. A clear shape-induced anisotropy is observed. The decrease in H_A observed at the smallest diameters is attributed to wire distortion. The activation volume deduced from magnetic aftereffect measurements is 6×10⁴ nm³. It is much larger than the one expected in the case of coherent rotation. Its value is rather consistent with a collective magnetization reversal process. The angular dependence of H_C approaches a 1/cos θ law. This behavior excludes coherent rotation. It is expected whenever the coercive field is much weaker than the anisotropy field in the activation volume

Keywords

coercive force; extrusion; induced anisotropy (magnetic); iron; magnetisation reversal; materials preparation; nanostructured materials; nanotechnology; 10 nm; Fe; activation volume; angular dependence; coercive force; collective magnetization reversal process; magnetic aftereffect; magnetic properties; multiple extrusions; nanometric wires; shape-induced anisotropy; wire distortion; Anisotropic magnetoresistance; Copper; Distortion measurement; Iron; Magnetic anisotropy; Magnetic properties; Magnetization reversal; Perpendicular magnetic anisotropy; Volume measurement; Wires;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.800565

Filename

800565