“Change in Magnetostriction Caused by Annealing in Fe-Ni and Co-Ni based Amorphous Alloys”

Abstract

Annealing effect on magnetostriction was studied for Fe₄₀Ni₄₀Si₂B₁₆ and Co₄₀Ni₄₀Si₈B₁₂ amorphous alloys. The λ_s in Fe-Ni based alloys is increased by annealing, while λ_s in Co-Ni based alloys is decreased. The relaxation process of λ_s in Fe-Ni based alloys, in which the one-ion term is dominant, can be described with a simple exponential curve having a low activation energy of 0.2eV. From the value of activation energy, it is inferred that the change in λ_s is basically associated with the topological short range order due to the excessive free volume and free from the compositional short range order. The λ_s in Co-Ni based alloys with the dominated two-ion term is responsible for the chemical short range order as the induced anisotropy.