Asymmetric GMI characteristics in current-biased amorphous (Co0.94Fe0.06)72.5Si12.5B15 wire

Abstract The giant magnetoimpedance (GMI) has been measured in as-quenched (Co0.94Fe0.06)72.5Si12.5B15 amorphous wire as a function of DC-biased current, Ib, along sample axis and measuring frequency f. The GMI profile during half a cycle of magnetization for Ib=0 shows a typical behavior of GMI, that is, single peak for f =0.1 MHz and symmetric two peaks for f ⩾0.5 MHz . Asymmetric GMI profile appears for I b ⩾0.85 mA in the frequency range between 0.1 and 10 MHz, due to the suppression of wall motion by the induced circular field. The field sensitivity amounted to 170%/Oe for 0.1 MHz with I b =3.4 mA and 150%/Oe for f ⩾0.5 MHz with 12.7 mA.