Comparative study of magnetoimpedance effect in current and field annealed (Co0.9Fe0.05Ni0.05)75Si15B10 amorphous ribbons

Magnetoimpedance (MI) and hysteresis loops in amorphous (Co0.9Fe0.05Ni0.05)75Si15B10 ribbons were measured to investigate the influence of current and field annealing. The results indicated that a transverse anisotropy was induced by both the magnetic field and current annealing methods. Using both techniques we succeeded in inducing the same magnitude of uniaxial anisotropy, Ku. It was observed that current annealed samples showed a larger MI effect. Since both samples have the same Ku, the difference in the magnitude of MI was explained by the domain structure. A positive MI effect, as large as 62%, was found in the 60 min current annealed sample at a 1 MHz driving frequency.