Characterization of amorphous FeZrB(Cu) alloys by the inductance spectroscopy method

Impedance spectroscopy measurements were carried out on amorphous ribbons of nominal compositions Fe93-x-yZr7BxCuy (x=6,8 and y=0,1,2), in the frequency range of 5 Hz-13 MHz. Two different geometries were used for measurements: a longitudinal one by using an 80-turn solenoid and the magnetoimpedance geometry, where the ac current flows through the ribbon itself. The obtained results showed a larger initial permeability value for longitudinal domain walls, as compared with transverse ones. Results concerning the propagation field showed the opposite behavior. These results are interpreted in terms of the short-range order arrangements of Fe atoms in these alloys, also known as "nanoamorphous demixing structures." (C) 2000 American Institute of Physics. [S0021-8979(00)25408-X].