Barkhausen avalanches in anisotropic ferromagnets with $180^\circ$ domain walls

TL;DR

This study investigates Barkhausen noise in 2D disordered ferromagnets with anisotropic domain walls, revealing how disorder and driving rate influence avalanche size distributions and aligning with experimental observations.

Contribution

It provides new insights into the scaling behavior and phase transition of Barkhausen avalanches in anisotropic ferromagnets under varying disorder and stress conditions.

Findings

Avalanche size exponent $ au_s$ is 1.54 at low disorder.

A dynamic phase transition occurs with increasing disorder, changing $ au_s$ to 1.30.

Exponents decrease with finite driving rate.

Abstract

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.