Analysis of the Domain Wall Motion in the Ion Irradiated Amorphous Ribbon

The mechanism of abrupt increase of the giant magneto impedance (GMI) ratio in the ion irradiated Co-based amorphous ribbon has been investigated. The GMI-ratio considerably increased in the ion irradiated samples and the GMI response showed strong dependence on the driving frequencies. The Barkhausen noise (BN) signals are decreased up to 46% for the Ar ion irradiated sample with energy of 100 keV. The power spectrum density of BN was decreased with increasing ion bombardment energy. The results are interpreted in terms of permeability variation associated with domain wall dynamics.