Influence of Metallic Core Diameter on Giant Magnetoimpedance Effect for Fe-based Nanocrystalline Microwires

Amorphous Fe_(73.5) Cu_1 Nb_3Si_(13.5) B_9,microwires were prepared by glass-coated melt spinning technique.Nanocrystalline samples were obtained by annealing the amorphous wires at 570℃.The diameter of the microwires varied between 16～50μm.The relationship between giant magnetoimpedance effect and the metallic core diameter was investigated.The results showed that the GMI ratios first increase then decrease with the increase of metallic core diame- ter.The highest magnetoimpedance ratio of 251% is obtained in the nanocrystalline microwire with 30μm in diameter.