Kl. Garcia et R. Valenzuela, Correlation between magnetization processes and giant magnetoimpedance response in CoFeBSi amorphous CoFeBSi wires, J NON-CRYST, 287(1-3), 2001, pp. 313-317
Giant magnetoimpedance (GMI) in amorphous (Fe0.06Co0.94)(72.5) B15Si12.5 wi
res (submitted to an alternative current, i(ac)) has a dependence of the im
pedance response, Z, on direct current magnetic field, H-dc. In as-cast wir
es, the ac current frequency changes the GMI: for frequencies of a few kHz,
the impedance response is a function of H-dc, having a single maximum at H
-dc = 0; for frequencies >1 MHz, however, two maxima (with a minimum at H-d
c = 0) are observed. By analyzing the frequency dependence of real, L-r, an
d imaginary inductance, L-i (proportional to real and imaginary permeabilit
y, respectively), we show that these results can be explained in terms of t
he dominant magnetization process: domain wall bulging for low frequencies,
and magnetization rotation for high frequencies. Plots of both L-r and L-i
as a function of frequency indicate relaxation processes at about 45 kHz,
due to a change from domain wall to spin rotation as the dominant magnetiza
tion process. (C) 2001 Elsevier Science B.V. All rights reserved.