Barkhausen noise of 3% Si-Fe strips after plastic deformation

Grain-oriented 3% Si-Fe strips were plastically strained up to
\epsilon = 3
%. The frequency spectrum
E(f)
of the Barkhausen noise was measured. From
E(O)
a mean Barkhausen volume v
eff
is calculated. The noise and v
eff
are diminished after plastic deformation mainly already in the region
\epsilon < 0.1
%, where the coercive field remains still constant, v
eff
is related to a mean irreversible susceptibility, which is mainly determined by the hysteresis loop. By measurements of the correlation of the flux changes along the specimen a mean length of the Barkhausen volumes was obtained. Its diminution mainly causes the diminution of v
eff
. The connection of the results with changes of the domain and dislocation structure is discussed.