Structure dependence of the magnetic-susceptibility behaviour at low magnetizing field

The magnetic susceptibility during hysteresis cycles was measured in both amorphous and crystalline metallic ribbons. The analysis of the dependence on magnetizing field evidences a different behaviour due to the structural differences. The fundamental importance of the amplitude of the magnetizing field used for dynamic evaluation of initial susceptibility is demonstrated and related to the measured effects as well. Moreover, both temperature and frequency effects on the initial susceptibility confirm some peculiar properties related to the amorphous character.