Role of Defects on Domain Wall Propagation in Magnetically Bistable Glass-Covered Microwires

Abstract

We are trying to reveal the contribution of local defects on DW propagation in amorphous microwires. Con- sequently, we present a comparative study of single domain wall dynamics and local nucleation fields in Fe- and Co-rich amorphous glass-coated microwires. For this we modified experimental set-up based on the classical Sixtus-Tonks ap- proach introducing additional pick-up coil in order evaluate defects contribution in domain wall propagation. Below some critical magnetic field, HN , determined by the microwires inhomogeneities, an almost linear DW ve- locity, v, dependence on magnetic field, H , is found. Quite fast DW propagation (v till 3000 m/s at H about 65 A/m) has been observed. When the applied magnetic field ex- ceeds HN , new reverse domains can be nucleated and con- sequently tandem remagnetization mechanism can be real- ized. The role of defects existing in magnetically bistable microwires is related with nucleation of new reversed do- mains.