Sound velocity in Fe-rich glass covered amorphous wires

The bias magnetic field (H) dependence of the longitudinal sound velocity ( v) in Fe77.5Si7.5B15 glass covered amorphous wires is reported. The amorpho us wires were tested in the as-cast state and after dc current annealing be tween 5 and 20 mA for 10-30 min. For the glass covered amorphous wires test ed in the as-cast state the bias magnetic field dependence of the sound vel ocity was insignificant. For current annealed samples a decrease of the sou nd velocity for the smaller bias magnetic fields was observed. Increasing t he annealing temperature, the bias magnetic field corresponding to the v(mi nimum) decreased. For about 600 A/m bias magnetic field, the longitudinal s ound velocity reaches saturation. (C) 2001 Elsevier Science B.V. All rights reserved.