Asymmetric giant magnetoimpedance in twisted CoFeCrSiB amorphous ribbons

The asymmetry of axial and off-diagonal impedance was investigated in as-quenched and field-annealed amorphous Co67Fe4Cr7Si8 B14 ribbons. The asymmetry of impedance characteristics can be controlled by DC bias current and torque. When an appropriate uniaxial anisotropy is superimposed very high field sensitivity (about 3000%/Oe) can be obtained. The proposed theoretical model well explains the observed behavior.