Negative Barkhausen jumps in amorphous ribbons of Fe63B14Si8Ni15

Negative Barkhausen jumps in amorphous ribbons of Fe63B14Si8Ni15 have been investigated both with the traditional inductive coil, which probes a large sample region, and also with a space resolved magneto-optical Kerr ellipsometer. After these negative jumps the magnetization vector is antiparallel with respect to the external field in the sample region where the reversal took place. Magneto-optical data indicate that negative jumps take place only in selected regions of the sample. The amplitude ΔM of both positive and negative jumps follows a power-law probability distribution: P(ΔM)=ΔM−α. The observed values of the critical exponent α are very similar, within the experimental error, both for positive and negative jumps (α=1.6).