Influence of pulsed current annealing on giant magneto-impedance effects of Co based amorphous ribbon

In this paper, the influence of pulsed current annealing on giant magneto-impedance (GM 1) effect of Co(66.3)Pe(3.7)Si(12)B(18) amorphous ribbon under different driving current is studied. The experiment results show that the GMI effect is closely related to the annealing current density. With the increase of annealing current density, the GM I ratio Delta Z/Z rises firstly and the maximal GMI ratio of 53.8% is obtained for the sample annealed at 104A/mm(2). When annealing current density increases further, the GMI ratio begins to decrease. The mechanism of the pulsed current annealing affecting the GMI effect is explained qualitatively. This paper also discusses the influence of transverse anisotropy field H-K induced by annealing on GMI effect. Proper transverse anisotropy field benefits the enhancement of the maximal GMI ratio, however, the GMI ratio will begin to fall as soon as exceeding the critical value.