Circumferential magnetization curves of Co-rich amorphous wires under tensile stress

Circumferential magnetization curves were obtained for low, negative magnet ostriction amorphous wires of nominal composition (Co0.94Fe0.06)(72.5)B15Si 12.5, under tensile stress up to 250 MPa, by using the magnetoimpedance eff ect. The various magnetization processes, i.e., spin rotation, domain wall bulging, and domain wall displacement were resolved by frequency measuremen ts in the 5 Hz-13 MHz range, and by varying the applied field amplitude bet ween 0.28 and 12 A/ m (root mean square). The results show that reversible magnetization processes (domain wall bulging and spin rotation) are damped by tensile stress, while the irreversible process (domain wall displacement ) is enhanced by stress. These results are interpreted in terms of an incre ase in anisotropy and a reorienting of magnetization in circumferential dom ains, both as a result of the stress-induced anisotropy. (C) 1999 American Institute of Physics. [S0021-8979(99)04501-6].