Low-frequency circumferential magnetization curves in magnetostrictive amorphous wires

Circumferential magnetization curves have been derived from the imaginary component of the impedance response in an Fe_73.5Si_13.5B₉Cu₁Nb₃ amorphous wire. Measurements were performed at 1 kHz driving frequency, and 0.05– 20 mA_rms current amplitude range. Axial DC fields from 0 to 100 Oe have been simultaneously applied in order to detect the magnetoinductive effect. The circular magnetization curves are compared with quasi-static longitudinal magnetization ones, and the results are analyzed on the basis of the core-shell model for a wire with positive magnetostriction.