Frequency dependence of the giant magnetoimpedance in current annealed amorphous wires

Abstract Frequency dependence in the range from 0.1 to 30 MHz of the giant magnetoimpedance effect (GMI) of DC current annealed iron-based amorphous wires is here presented. The as-cast amorphous samples presents a uniform increase of the phase angle between the real and imaginary part of the complex impedance with frequency. When annealing with increasing current density a clear peak of the phase angle is present, revealing the induction of circular anisotropy accompanied by and increase of the GMI percent.