Structural relaxation and magnetic properties of Co-rich amorphous wire

Abstract

Thermal treatment in the presence of either a magnetic field and applied tensile stress have been carried out in a Co-rich nearly non-magnetostrictive amorphous wire. Structural relaxation is followed by an evaluation of the induced magnetic anisotropy and changes in the saturation magnetostriction after treatment. The orientation of the easy axis of induced anisotropy depends on the annealing conditions. The magnetostriction is modified as structural relaxation proceeds, irrespective of the orientation of the induced preferred axes. This suggested that although the origin of the induced anisotropy (i.e. field anisotropy) can be ascribed to the generation of atom pairs, the changes in magnetostriction are related to topological-like atomic rearrangements. Both mechanisms develop simultaneously so that overlapping effects can sometimes mask the origin of the changes in these quantities. Moreover, as in case Co-rich amorphous ribbons, the stress dependence of magnetostriction follows the law λ = λ 0 – ασ, for as-cast and annealed wires.