Magnetoelastic hysteresis of amorphous ribbons

The influence of tensile stress on hysteresis loops and the magnetomechanical effect in high-magnetostrictive Fe-rich and low-magnetostrictive Co-rich amorphous ribbons were investigated. In the as-quenched Fe-rich alloy a very complex behavior is observed, which indicates the interplay of different types of magnetization processes. Uniaxial magnetic anisotropies, induced by stress annealing, eliminate the rotational processes in Fe-rich materials and the domain-wall motion in Co-rich materials. Thus, the role of the two different mechanisms in the magnetoelastic hysteresis can be studied separately. It is shown that irreversible domain-wall movements are responsible for the large hysteresis in the Fe-rich alloy, while the purely rotational magnetization process can account for the essentially anhysteretic behavior of the Co-rich alloy. The theoretical model by Livingston [J. D. Livingston, Phys. Status Solidi 70, 591 (1982)] can well explain the anhysteretic behavior.