GIANT MAGNETO-IMPEDANCE EFFECT IN NANOCRYSTALLINE FE73.5CUNB3SI13.5B9RIBBONS

Magneto-impedance (MI) effects have been observed in amorphous and nan ocrystalline Fe73.5Cu Nb3Si13.5B9 ribbons. Large MI values have been o btained in nanocrystalline samples (NCS), but not in as-quenched sampl es (AQS). The magnetic responses of impedance of nanocrystalline sampl es share some common features with that of Co-based amorphous wire and ribbon samples. The field dependencies of effective permeability for nanocrystalline samples have shown a sharp change at the anisotropy fi eld. The effective permeability and the hysteresis loops for AQS and N CS have been shown to be responsible for their MI effects. The sensiti vity of the magnetic responses in the nanocrystalline sample can reach 50%/Oe.