Giant magnetoimpedance in thin amorphous wires: From manipulation of magnetic field dependence to industrial applications

We present the results on tailoring of soft magnetic properties and GMI effect in thin microwires paying special attention on achievement of low hysteretic high GMI effect in the extended frequency range (up to 4 GHz). We observed considerable dependence of the GMI ratio and magnetic anisotropy field, Hk, of Co-rich amorphous microwires with vanishing magnetostriction constant on the internal and applied stresses. For low magnetostrictive Co-rich composition we obtained microwires low coercivity values (generally below 10 A/m). Field dependence of the off-diagonal voltage response measured in pulsed regime (pulsed GMI) exhibits anti-symmetrical shape.The magnetic anisotropy of Co and Fe-rich microwires can be tailored by stress or magnetic field annealing. Particularly stress annealed Fe-rich microwires exhibit stress-sensitive GMI effect and hysteretic properties. Varying the time and the temperature of such stress annealing we are able to tailor both magnetic properties and GMI. Additionally, magnetic response of linear microwires arrays and GMI effect of the system containing few microwires can be tailored through the magnetostatic interaction between the microwires.We found, that if the surface anisotropy is not circumferential, then the MI curve Z(H) presents hysteresis. This hysteresis can be suppressed by application of sufficiently high DC bias current IB that creates a circumferential bias field HB.

► Systematic studies of the optimization of magnetic properties and GMI effect of microwires.
► Systematic study of the effect of magnetoelastic anisotropy on magnetic properties of microwires.
► Contextual discussions of the impact of magnetoelastic anisotropy on GMI effect of microwires.
► Systematic study of effect of magnetostatic interactions on magnetic properties of microwires.
► Contextual discussions of magnetic microwires applications for magnetic microsensors.