Effects of chemical etching on the asymmetric magnetization reversal in amorphous magnetic alloy

Intensive etching experiments have been performed in order to investigate the origin of asymmetric magnetization reversal (AMR), which can be developed in amorphous ferromagnetic ribbons annealed in a controlled magnetic field. The variation of the characteristics of AMR with etching time was analyzed from dc magnetic hysteresis loops measured in situ during etching. The AMR characteristics were altered very rapidly and severely just after most of the outer oxide layer was removed, but did not disappear until 30% of the volume of the as-annealed sample had been etched away. From Auger depth profile analysis and domain observations, we conclude that the major origin of AMR resides in a high coercive layer between the oxide layer and the bulk material