Barkhausen noise in ferromagnetic metallic glass $Fe_{40}Ni_{38}Mo_4B_{18}$

Abstract

The Barkhausen Noise (BN) and its energy have ben studied during the magnetization cycle in a ferromagnetic amorphous $Fe_{40}Ni_{38}Mo_4B_{18}$. Experiments are carried out for unannealed and annealed specimens to study the influence of heat treatment on the BN. The magnetic properties as well as the BN strongly depend on the state of specimens after annealing. The abrupt change of permeability, coercivity, saturation magnetization and BN energy were closely related to the onset of crystallization. The BN energy increases with increasing applied magnetic field and magnetizing frequency. But increasing rate of the BN energy depends on the states of the specimens. These results are explained by microstructure, hysteresis loop parameters and domain wall mobility.