Comparative study of the giant magneto-impedance effect in CoFeSiB magnetic amorphous ribbons and wires

We present a comparative study of the magneto-impedance effect in Co68.15Fe4.35Si12.5B15 amorphous ferromagnetic wires and ribbons. The magneto-impedance measurements indicate that the magneto-impedance effect is generally more sensitive in the wire-shaped samples in comparison with the ribbon-shaped ones. The obtained results are interpreted on the basis of the circumferential magnetic permeability of the wire and the transverse permeability of the ribbon, correlated with the specific magnetic domain structures.