Annealing effects in Ni-based amorphous alloys with dilute concentrations of Fe

Abstract

The melt‐spun amorphous Fe_cNi_80−c P₁₄B₆ alloys show spin‐glass behavior for c?5, and mictomagnetic behavior for 5<c<∼10. We show that spin‐glass behavior is insensitive to annealing treatments below 300° C, which is well below temperatures that produce crystallization. The mictomagnetic alloys are slightly influenced by such treatments. This result suggests a long‐range nature for the magnetic interactions in the spin‐glass state. Annealing at 350° C results in the appearance of ferromagnetism, without obvious devitrification. The exact nature of this transformation is still not known.