We investigate the Barkhausen noise in ferromagnetic thin films with zigzag domain walls. We use a cellular automaton model that describes the motion of a zigzag domain wall in an impure ferromagnetic quasi-two dimensional sample with in-plane uniaxial magnetization at zero temperature, driven by an external magnetic field. The main ingredients of this model are the dipolar spin spin interactions and the anisotropy energy. A power law behaviour with a cut-off is found for the probability distributions of size, duration and correlation length of the Barkhausen avalanches, and the scaling exponents are in agreement with the available experiments. The link between the size and the duration of the avalanches is analysed too, and a power law behaviour is found for the average size of an avalanche as a function of its duration.
Barkhausen noise from zigzag domain walls
Zapperi S
2006
Abstract
We investigate the Barkhausen noise in ferromagnetic thin films with zigzag domain walls. We use a cellular automaton model that describes the motion of a zigzag domain wall in an impure ferromagnetic quasi-two dimensional sample with in-plane uniaxial magnetization at zero temperature, driven by an external magnetic field. The main ingredients of this model are the dipolar spin spin interactions and the anisotropy energy. A power law behaviour with a cut-off is found for the probability distributions of size, duration and correlation length of the Barkhausen avalanches, and the scaling exponents are in agreement with the available experiments. The link between the size and the duration of the avalanches is analysed too, and a power law behaviour is found for the average size of an avalanche as a function of its duration.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
