Magnetoresistance Magnetometry of (Ni80Fe20)1-xIrx Wires with Varying Anisotropic Magnetoresistance Ratio

Published

May 1, 2003

Author(s)

C A. Vaz, E Blackburn, M Klaui, J A. Bland, L Gan, William F. Egelhoff Jr., E Cambril, G Faini, W Wernsdorfer

Abstract

We report room and low temperature magnetoresistance measurements on sub-micrometer scale elements (wires and crosses, 1.0, 0.5 and 0.1 m) of (Ni₈₀Fe₂₀)_1-xIr_x (x approximately equal} 2 %) with varying Ir concentrations. For the particular Ir concentrations studied, the anisotropic magnetoresistance(AMR) ratio varied between -0.043% and -0.035% at room temperature. For thesingle wires (0.5- 1 υm) the MR versus eld characteristic is similar to that reported for (Ni₈₀Fe₂₀) wires of similar size, but an opposite sign of the AMR is observed for x > 2 %. For H parallel to the wire axis, the reversal is determined by the sweeping of a few domains which give rise to 'ears' in the MR-Hcharacteristic. For H perpendicular to the wire, a parabolic variation is seen corresponding torotation of the magnetisation, but a negative slope in the MR-H characteristic is obtained at high fields as in permalloy wires. This suggests that the high field behaviour originates from a distinctly different mechanism (e.g., surface scattering) from that of AMR.

Citation

Journal of Applied Physics

Volume

93

Issue

No. 10

Pub Type

Journals

Keywords

domains, Ir alloy, magnetoresistance, permalloy, surface scattering

Citation

Vaz, C. , Blackburn, E. , Klaui, M. , Bland, J. , Gan, L. , Egelhoff Jr., W. , Cambril, E. , Faini, G. and Wernsdorfer, W. (2003), Magnetoresistance Magnetometry of (Ni₈₀Fe₂₀)_1-xIr_x Wires with Varying Anisotropic Magnetoresistance Ratio, Journal of Applied Physics (Accessed April 25, 2024)