Determinism and correlation dimension of Barkhausen noise

Abstract

Barkhausen noise ͑BN͒ is measured in an amorphous ribbon in an open magnetic circuit. The experiment is set up in such a way as to obtain the BN signal with a high frequency range and low apparatus noise. The driving field is produced by a pair of Helmholtz coils and the pick-up coil is a low capacity radio coil. The signal is amplified by a custom designed two-stage, battery operated amplifier, which together with the coils and the ferromagnetic ribbon is screened by three coats of soft iron. The data acquisition is done by a 12-bit analog-digital card allowing one to obtain up to 1ϫ10 6 data points with a sampling frequency up to 1 MHz. The correlation dimension of the BN signal is calculated using the Grassberger-Procaccia algorithm and the surrogate data method is used to exclude artifacts. The choice of the measurement conditions and the calculation parameters is discussed. The results show a low dimensionality of the Barkhausen noise that leads to the conclusion that the effect may contain or is caused by a deterministic mechanism. The experimental method allows one to obtain the BN signal over many magnetic reversals so that the repeatability of the results is shown and statistics on the correlation dimension values are performed. ͓S1063-651X͑98͒06106-6͔

Barkhausen noise in the random field Ising magnetNd2Fe14B

“…This is the behavior typically observed in Barkhausen experiments on magnetically soft and amorphous materials such as ferroglasses. [38][39][40][41][42] By contrast, increasing the depth of a showing the evolution of the free energy landscape when a transverse field is applied. The transverse-field-induced random field tunes the system from the weak to the strong disorder limit, resulting in deeper local minima in the energy landscape, where the magnetization can oscillate about these minima.…”

Cooperative motion of domain walls in magnetic multilayers

“…However, a handful of insightful previous studies have shown limited reproducibility in small field excursions, in small samples, or over small distances. [74][75][76][77][78][79] The reproducibility of magnetic avalanches in the present study occurs along the entire major magnetization loop, and the same set of emf avalanches are reproducibly transmitted over macroscopic distances. The observed reproducibility has its origins in the highly synchronized and cooperative motion of domain walls in different layers.…”

A spring-block model for Barkhausen noise

“…The experimental results for the signal duration and the signal area [3,8] distribution indicated a powerlaw behavior for both quantities. For the signal duration distribution the measured exponents were −2.2 [3] and −1.64 to −1.82 [8]. Although there is a strong difference between these results, the experiments agree in the validity of the power-law distribution.…”

“…Numerous measurements were done to clarify the statistical properties of the BN [2][3][4]. Regarding the nature of the Barkhausen noise (white noise, 1/f noise, or 1/f 2 noise) even the experimental results are incoherent with each other.…”

“…From here they concluded that BN is not pure 1/f , nor 1/f 2 (Brownian) type noise, but something between these two. Plewka, et al [3] performed measurements (and calculations) with a similar experimental setup on an amorphous ribbon in an open magnetic circuit. They obtained instead a value around −0.9 for the scaling exponent of the power spectrum.…”