Barkhausen avalanches in anisotropic ferromagnets with 180 degrees domain walls
We show that Barkhausen noise in two-dimensional disordered ferromagnets with extended domain walls is characterized by the avalanche size exponent tau(s)=1.54 at low disorder. With increasing disorder the characteristic domain size is reduced relative to the system size due to nucleation of new domains and a dynamic phase transition occurs to the scaling behavior with tau(s)=1.30. The exponents decrease at finite driving rate. The results agree with recently observed behavior in amorphous Metglas and Fe-Co-B ribbons when the applied anisotropic stress is varied.
Tadic
B
Jozef Stefan Institute, P.O. Box 3000, 1001 Ljubljana, Slovenia.
Nowak
U