Magneto-impedance in Co-based amorphous wire and ribbon

Magneto-impedance of Co-based amorphous alloys with low maganetostriction ( lambda) and in the form of wire and ribbon is measured as a function of lon gitudinal d.c. magnetic field (H) for frequencies up to 100 KHz. Nearly 100 % drop in reactance is found in wire and ribbon with small and negative lam bda for H approximate to 30 Oe. The field sensitivity of impedance goes dow n for alloys with higher values of lambda. The longitudinal external stress reduces the reactance. (C) 2001 Published by Elsevier Science B.V.