The Effect of DC Bias Current on Domain Wall Resonance Property of Thin-Film Magnetoimpedance Element

We investigated the influence of the dc bias current on the domain wall resonance of thin-film magnetoimpedance (MI) elements. When the intensity of dc bias current is relatively low (0-0.5 mA), the impedance profile shows a domain wall resonance behavior, which shows another peak and rapid drop of inductance in the low-frequency region. The peak height and resonance frequency do not depend on the dc bias current in this range. On the other hand, though the impedance profiles still show domain wall resonance, the behavior strongly depends on the dc bias current; the impedance peak height and amount of inductance drop decrease as well as the resonance frequency shifts to lower frequency with increasing dc bias current. The domain wall resonance completely disappears at 2 mA in this study. On the static field dependence of impedance with dc bias current, the profile shows asymmetric with respect to the Z-axis, which is the same as the property observed in higher frequency. The slight increment of impedance and inductance changes was admitted around the resonance frequency.