Giant magnetoimpedance effect and magnetoelastic properties in stress-annealed FeCuNbSiB nanocrystalline wire

Stress-current annealing performed on Fe_73.5Cu₁Nb₃Si_13.5B₉ amorphous wire results in ultra-soft "nanocrystalline" wire with an additional very homogeneous transverse magnetic anisotropy. The giant magnetoimpedance (GMI) response of this treated wire has been investigated in a range of ac current (I_ac = 0.2 to 20 mA) and frequency (f = 0.01 to 1 MHz). A maximum GMI ratio as high as around 150% is reported. The magnetoelastic behavior and in particular the influence of applied tensile and torsional stresses, has been analyzed in connection with GMI. From the applied stress dependence of the static field H_m at which the maximum impedance is observed, the values of induced anisotropy field (H_ind = 3.46 and 3.14 kA/m) and magnetostriction (λ_s = 1.42 and 1.59 × 10^-6) are determined.