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 amorphous wires were tested in the as-cast state and after dc current annealing between 5 and 20 mA for 10–30 min. For the glass covered amorphous wires tested in the as-cast state the bias magnetic field dependence of the sound velocity was insignificant. For current annealed samples a decrease of the sound velocity for the smaller bias magnetic fields was observed. Increasing the annealing temperature, the bias magnetic field corresponding to the vminimum decreased. For about 600 A/m bias magnetic field, the longitudinal sound velocity reaches saturation.