Magnetostrictions of Fe_73.5−x Ni _x Cu₁Nb₃Si_13.5B₉ upon its transformation onto nanocrystalline phases

Abstract

Transformation processes from amorphous to nanocrystalline structure are manifest in the alloy system Fe_73.5−x Ni _x Cu₁Nb₃Si_13.5B₉ upon thermal treatment. Measurements of magnetostriction quantities λ_‖(H), λ_{⊥ (H)}, λ_S and ∂ω/∂H reflect these processes. The dependence of λ_‖(H) points to the existence of at least two types of formations already within the amorphous phase which have different magnetization curve. After a specific thermal treatment nanocrystals rich in Fe and Ni are formed. The variations of λ_S and ∂ω/∂H reflect the ongoing transformation process. The value of λ_S decreases with increasing concentration by more than 50%. The spontaneous volume magnetostriction decreases with increasing Ni concentration in amorphous state.