Magnetoimpedance Response in Co-Based Amorphous Ribbons Obtained Under the Action of a Magnetic Field

Magnetoimpedance (MI) response in the frequency range of 10-1000 MHz of Co69Fe4Si15B12 amorphous ribbons obtained by rapid solidification without and with a magnetic field of 56 kA/m applied in the transverse direction of the ribbon during the fabrication is reported. MI of the ribbon produced without magnetic field presents one-peak behaviour at low frequency (<50 MHz) emerging two-peaks above this frequency, while the two-peaks is present at all frequencies for the ribbon produced with magnetic field as a consequence of the transverse magnetic anisotropy induced during the fabrication process. The evolution of the maximum of MI with the axial magnetic field, ascribed to the anisotropy field, as a function of the frequency provides useful information on the ribbons magnetic inhomogeneity through their cross section.