Structural Characterization and Magnetoimpedance Effect of Current Annealed Co-Based Amorphous Ribbons at Different Ambient

摘要

The effect of current annealing in the air and vacuum on structure and magnetoimpedance (MI) response of Co-68.15 Fe-4.35 Si-12.5 B-15 amorphous ribbons was investigated. After 15 min of annealing, we found optimized currents where maximum MI ratio reached to 125 % and 160 % for annealing in the air and vacuum, respectively. Sample structures and their magnetic properties were investigated to explain the MI response after the annealing. Variation of MI responses can be correlated to the difference in the thermal conductivity of air and vacuum, field-induced anisotropy, and surface changes.