Engineering of Magnetic Properties of Co- and Fe-Rich Microwires

We present our experimental results on optimization of the magnetic softness, domain wall (DW) dynamics, and giant magnetoimpedance (GMI) effect of Fe- and Co-rich microwires. It is found that the as-prepared Co-rich microwires possess much higher GMI effects and linear hysteresis loop. On the other hand, the magnetic softness and GMI effect of Fe-rich microwires can be improved by stress annealing. In addition, the DW velocity of the microwires can be considerably improved by annealing. The single DW propagation can also be observed in properly annealed Co-rich microwires. These observed dependencies can be attributed to the relaxation of internal stresses after annealing and the interplay of compressive stresses and axial internal stresses after stress annealing.