Bias-current effect on giant magnetoimpedance in Co-based amorphous microwire

The giant magnetoimpedance (GMI) effect has been measured in Co83.2B3.3Si5.9Mn7.6 amorphous microwire as a function of direct current (dc)-biased current and measuring frequency, f. The GMI profile has a single peak for f⩽5 MHz, and two peaks at higher frequency. The maximum GMI ratio increases continuously with frequency up to 45% at 10 MHz. The influence of superimposed dc biasing is shown to result in asymmetrical GMI as well as in a shift of the axial hysteresis loop. Both effects are interpreted in terms of the relative contribution of domain wall and rotational processes to the transverse susceptibility.