High-resolution ΔE measurements of Fe-Si-B amorphous wire

The field dependence of Young´s modulus, E(H), of as-cast Fe-based amorphous wire has been investigated using a high resolution vibrating reed system. The E(H) data have been combined with DC M(H) loops and Kerr effect surface domain images to provide information about the effect of the large Barkhausen jump which characterizes the magnetization reversal in this material. At low fields the modulus decreases via an abrupt small step which correlates with the field at which the large Barkhausen jump occurs in the M(H) behavior. It is suggested that the reversal of the magnetization in the core domain leads to a slight rearrangement of domains in the sheath region of the wires. This is supported by the surface domain images and indicates a small asymmetry in the remanence states