Investigation of the damping parameter in soft magnetic wires using the giant magnetoimpedance effect

We construct a simple model of the high frequency impedance applicable to s oft magnetic wires and derive an expression which relates the Landau-Lifsch itz damping parameter, lambda, to the peak value of the wire impedance at f erromagnetic resonance. Measurements on a ferromagnetic Co68.15Fe4.35Si12.5 B15 amorphous magnetic wire are characterized by resonance peaks which vary significantly in amplitude and width as a function of the applied field. T hese results can be accounted for by a near exponential field dependence of the damping parameter at high magnetic fields. We suggest that this behavi or results from inhomogeneities in the sample properties. (C) 1999 Elsevier Science B.V. All rights reserved.