IMPLICATIONS OF MAGNETIC AND MAGNETOELASTIC MEASUREMENTS FOR THE DOMAIN-STRUCTURE OF FESIB AMORPHOUS WIRES

The field-dependence of magnetization, Young's modulus and magnetostriction have been used to investigate the domain structure of FeSiB amorphous wires. The experimental observations of the as-cast wire are explained in terms of a modified core-shell model in which the shell is magnetized in a series of domains oriented approximately perpendicular to the wire axis and the magnetization in the core is oriented at an average angle of about 440 to the wire axis. The presence of reverse spike domains in the core at the ends of the wire is also suggested. The critical length below which magnetic bistability is lost may be associated with these reverse domains. The behaviour of wires annealed at 425-degrees-C can be interpreted in terms of a similar model, except that the core volume and the length of the reverse spike domains are increased and the average magnetic moment angle in the core is decreased.