Phenomenology and interpretation of the Barkhausen effect in ferromagnetic materials (invited)

Abstract

After reviewing the main aspects of Barkhausen effect (BE) phenomenology and the principal theoretical models proposed for its interpretation, a new experimental and theoretical approach is presented. It is shown that definite progress in the comprehension of BE phenomenology is achieved by restricting BE experiments to the central part of the hysteresis loop, where BE behaves as a stationary stochastic process and domain wall motion is the dominant magnetization process. From the theoretical point of view, a critical reconsideration of literature results on domain wall dynamics is proposed, which leads to a Langevin equation for BE, whose solution provides definite analytic expressions for BE power spectrum and amplitude probability distribution. A comparison between the obtained theoretical predictions and typical experimental results is presented and discussed.