Effect of Annealing on Magnetic Properties and Giant Magnetoimpedance Effect of Amorphous Microwires

We report on the magnetic properties and giant magnetoimpedance (GMI) effect of amorphous glass-coated Co-rich microwires in as-prepared and annealed states. The magnetic field and frequency dependences of GMI, magnetic hysteresis loops, and domain wall (DW) dynamics of Co_69.2Fe_4.1B_11.8Si_13.8C_1.1 microwires produced by the Taylor-Ulitovski technique were investigated systematically. We have shown that these properties can be tailored either by controlling magnetoelastic anisotropy of the as-prepared microwires or by controlling their magnetic anisotropy via proper annealing. While the GMI effect has been achieved in an as-prepared microwire, high DW velocity and rectangular hysteresis loops have been observed in its annealed counterpart.