Engineering of magnetic properties and domain wall dynamics in Fe-Ni-based amorphous microwires by annealing

We present experimental studies related to the influence of annealing on domain wall (DW) dynamics and magnetic hysteresis of Fe-Ni-rich microwires. As-prepared and annealed Fe62Ni15.5Si7.5B15 and Fe49.6Ni27.9Si7.5B15 microwires present perfectly rectangular hysteresis loops and single DW propagation. DW velocity, v, DW mobility, S, and coercivity, Hc, of both studied microwires have been considerably affected after annealing. In Fe62Ni15.5Si7.5B15 microwires, we observed a gradual S increase with annealing time, tann, increasing. However, a non-monotonic S (tann) dependence was observed in Fe49.6Ni27.9Si7.5B15 microwires. We discussed observed dependencies in terms of different magnetoelastic anisotropy, domain walls stabilization, and different Curie temperatures of studied microwires.