EFFECT OF MAGNETIC-STRUCTURE ON GIANT MAGNETO-IMPEDANCE IN CO-RICH AMORPHOUS-ALLOYS

We present a review of the giant magneto-impedance (GMI) in Co-rich am orphous wires and films, in which effects with sensitivity up to 100 a nd 8%/Oe, respectively, have been reported even for tiny samples. GMI, a side-effect of the skin effect, depends considerably upon the parti cular magnetic structure and frequency range. Considering the differen t magnetic anisotropies (circumferential or helical in a wire, and tra nsverse in a film), various types of GMI characteristics can be obtain ed: having a maximum or minimum at zero external field, without a hyst eresis or exhibiting a sharp bistable hysteresis, symmetrical or asymm etrical with respect to the field. This suggests great technological p otential of GMI in a wide range of sensor applications.