Influence of Cu and Ta on the stress induced anisotropy in FeSiB amorphous ribbons

We have studied the effect of the Cu and Ta additions on the induction of magnetic anisotropies in FeSiB melt spun amorphous ribbons. The induction process was performed by using the current annealing technique with (and without) the simultaneous application of a longitudinal (parallel to the ribbon axis) tensile stress. We observed that when low intensities are used during the induction process the resulting anisotropy has a longitudinal easy axis. On the contrary, when the induction treatment is carried out by making flow through the samples a high intensity current the resulting effective anisotropy is dominated by the precipitation of crystallites corresponding to the first stage of the crystallization process. We also observed that the treatments carried out under tensile stress (stress anneals) produced in all the cases a smaller induced anisotropy than those performed without that applied stress (stress-free anneals)