Off-diagonal magnetoimpedance in stress-annealed amorphous ribbons

The influence of creep-induced magnetic anisotropy on the off-diagonal magnetoimpedance in amorphous Co₆₇Fe₄Cr₇Si₈B₁₄ ribbon is investigated. Hard-ribbon-axis anisotropy is produced by continuous stress annealing. On applying DC bias current, the off-diagonal impedance becomes an antisymmetric function of applied field with a quasi-linear part around the zero field. Theoretical explanation of the phenomenon is based on classical electrodynamics. It is shown that the maximum on the frequency dependence of off-diagonal impedance, observed around 1 MHz, results from competition between the electromagnetic induction and the skin effect. The quasi-linear characteristic can be utilized in low-cost high-sensitive magnetic field sensors.