Asymmetric magnetoimpedance in amorphous microwires due to bias current: Effect of torsional stress

The influence of torsional stress on the asymmetric magnetoimpedance in a glass-coated negative magnetostrictive amorphous microwire due to bias current is studied theoretically. The longitudinal and off-diagonal impedance components are found assuming a simplified spatial distribution of the magnetoelastic anisotropy induced by the torsional stress. The asymmetry in the field dependence of the impedance components is attributed to the combination of the circular magnetic field produced by the bias current and a helical anisotropy induced by the torsional stress. The asymmetry in the magnetoimpedance and the low-field hysteresis are analyzed as a function of the bias current and torsional stress. It is shown that the application of torsional stress significantly changes the value of the bias current required to suppress the hysteresis effect. The results obtained may be useful for applications in magnetic-field and stress sensors. •Effects of torsional stress on magnetoimpedance in amorphous microwire are studied.•Asymmetry in magnetoimpedance is analyzed as a function of bias current and stress.•Torsional stress changes the anisotropy and effects on the microwire impedance.•Field-dependence of impedance is anhysteretic when bias current exceeds threshold value.•Threshold bias current can be tuned by the application of torsional stress.