Off-diagonal magnetoimpedance effect in field quenched Co69Fe4Si15B12 amorphous ribbons

In this work, the off-diagonal magnetoimpedance (MI) effect in two types of Co69Fe4Si15B12 amorphous ribbons was measured. One type of ribbons was obtained by means of the conventional melt spinning technique. The other type of ribbons was obtained by the same procedure but with an applied transverse bias magnetic field, in order to induce a transverse anisotropy across the ribbon plane. According to our results, this field quenching procedure induces a small and homogeneously distributed anisotropy that improves the off-diagonal impedance response in all the frequency range here measured. In the as-quenched ribbon without field, slightly asymmetric two-peak behaviour of the field depending off-diagonal impedance at a frequency higher than its corresponding relaxation frequency has been observed. This can be related to the coupling among ribbon layers with different magnitude and/or orientation of the anisotropy induced by the developed stresses during the fabrication process.