Effect of annealing on the giant magneto-impedance in amorphous CoFeSiB ribbons and wires

Abstract
The results of the effect of annealing on the giant magneto-impedance response of CoFeSiB amorphous wires and ribbons with nearly zero magnetostriction are reported. The most sensitive magneto-impedance response is given by amorphous wires in every case. Annealing reduces the magnitude of the magneto-impedance both for ribbons and wires, due to the alteration of the favorable transverse domain structure that exists in the as-cast samples. Annealing at more elevated temperatures tends to increase the magneto-impedance almost to its initial value for the as-cast samples, due to the stress relief accompanied by the improvement of soft magnetic properties.