Effect of Nanoscale Magnetic Coating on the Dynamic Rearrangement of Domain Wall Structures in Magnetic Microwires

We investigate the influence of magnetic Co coatings on the mobility of magnetic domain walls in glass-coated Fe-rich amorphous microwires. By combining fluxmetric measurements and the Sixtus-Tonks method, we analyze how coatings of different thickness modify magnetization reversal and domain wall propagation. Magnetic cobalt coatings affect domain wall dynamics via magnetostatic interaction: the stray fields generated by the Co shell superimpose with the external field, producing a smooth, field-dependent acceleration of domain wall motion. The velocity enhancement depends on coating thickness and geometry, reflecting a balance between domain wall tension, magnetic pressure, and stray field contribution. Analytical and numerical calculations of the stray field generated by a cobalt hollow cylinder provide a physically consistent picture of how a thin magnetic coating may influence domain wall mobility. The edge of the cobalt coating plays a key role in the spatial reorganization of the field, where axial and radial components simultaneously change, and this is proposed as a plausible mechanism for the observed transformation of the domain structure.