Dynamics of a ferromagnetic domain wall: avalanches, depinning transition and the Barkhausen effect

Details Dynamics of a ferromagnetic domain wall: avalanches, depinning transition and the Barkhausen effect Dynamics of a ferromagnetic domain wall: avalanches, depinning transition and the Barkhausen effect

1998-03-20

arxiv.org/abs/cond-mat/9803253v1

Physics

Condensed Matter

Statistical Mechanics

17 RevTeX pages, 19 embedded ps figures + 1 extra figure, submitted to Phys. Rev. B

Scientific paper

10.1103/PhysRevB.58.6353

We study the dynamics of a ferromagnetic domain wall driven by an external magnetic field through a disordered medium. The avalanche-like motion of the domain walls between pinned configurations produces a noise known as the Barkhausen effect. We discuss experimental results on soft ferromagnetic materials, with reference to the domain structure and the sample geometry, and report Barkhausen noise measurements on Fe$_{21}$Co$_{64}$B$_{15}$ amorphous alloy. We construct an equation of motion for a flexible domain wall, which displays a depinning transition as the field is increased. The long-range dipolar interactions are shown to set the upper critical dimension to $d_c=3$, which implies that mean-field exponents (with possible logarithmic correction) are expected to describe the Barkhausen effect. We introduce a mean-field infinite-range model and show that it is equivalent to a previously introduced single-degree-of-freedom model, known to reproduce several experimental results. We numerically simulate the equation in $d=3$, confirming the theoretical predictions. We compute the avalanche distributions as a function of the field driving rate and the intensity of the demagnetizing field. The scaling exponents change linearly with the driving rate, while the cutoff of the distribution is determined by the demagnetizing field, in remarkable agreement with experiments.

Affiliated with

Also associated with

No associations

Rating

Dynamics of a ferromagnetic domain wall: avalanches, depinning transition and the Barkhausen effect does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Dynamics of a ferromagnetic domain wall: avalanches, depinning transition and the Barkhausen effect, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Dynamics of a ferromagnetic domain wall: avalanches, depinning transition and the Barkhausen effect will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-343991