Stress induced anisotropy and temperature dependence of the magnetostriction in Fe_73.5Cu₁Nb₃Si _13.5B₉ amorphous alloy

The magnetic anisotropy, K_σ, induced by heating under applied tensile stress has been studied for the Fe_73.5Cu ₁Nb₃Si_13.5B₉ amorphous alloy as a function of the annealing temperature. The induction process was carried out by means of current annealing in samples as-quenched and preannealed (T _P.A.=400°C during 2 min). It is found that the easy axis of this anisotropy is transverse to the tensile stress. The dependence of the stress induced anisotropy on annealing temperature is, in both cases, similar to that reported in other different metallic glasses when annealing at temperature below T_c=350°C, while K_σ is practically constant (≊500 J m^-3) in the annealing temperature range from 350 to 525°C. On the other hand, the magnetostriction constant, λ_s, was determined as a function of the measuring temperature within the range from 4.2 K up to 600 K. The results can be well accounted for by the single-ion model up to 350 K, while above this temperature the contribution of two-ion mechnism is also inferred.