The analysis of magnetoimpedance by equivalent circuits

Abstract Simple circuits formed by resistors, inductors and capacitors can be used to model giant magnetoimpedance (GMI) with a good approximation. Three different circuits are found to represent GMI in the whole frequency range (100 Hz–9 GHz) and the AC magnetic field amplitude range (0.01–7.22 A/m RMS): a series R s C s L s , a parallel R p L p and a parallel R H L H , associated with the magnetization processes of spin rotation (leading to ferro-magnetic spin resonance), domain wall bulging (initial permeability) and domain wall displacement (magnetic hysteresis), respectively. We also propose a correlation between these elements and physical parameters of the sample, such as permeabilities, domain wall damping parameters and domain wall effective mass.