Barkhausen noise in soft amorphous magnetic materials under applied stress

Amorphous and Nanocrystalline Soft Magnetic Materials

Annealing of amorphous precursor alloys, with compositions (Fe,Co!88M7B4Cu1 ~M5Zr, Nb, Hf!, above their primary crystallization temperature results in the nanocrystallization of the ferromagnetic a8-FeCo phase. This work describes results of the characterization of these alloys, including morphological and chemical stability of the a8-FeCo phase, examination of alloy compositions, and developme...

Statistical properties of Barkhausen noise in amorphous ferromagnetic films.

We investigate the statistical properties of the Barkhausen noise in amorphous ferromagnetic films with thicknesses in the range between 100 and 1000 nm. From Barkhausen noise time series measured with the traditional inductive technique, we perform a wide statistical analysis and establish the scaling exponents τ,α,1/σνz, and ϑ. We also focus on the average shape of the avalanches, which gives...

Atomistic simulations of magnetic amorphous solids: Magnetostriction, Barkhausen noise and novel singularities

Bi-axial Stress Effects on Barkhausen-Noise

Mechanical stress has a strong effect on the magnitude of the Barkhausen-noise in structural steels. Because the measurements are performed at the surface of the material, for a sample sheet, the full effect can be described by a biaxial stress field. The measured Barkhausen-noise is dependent on the orientation of the exciting magnetic field relative to the axis of the stress tensor. The sampl...

Effeci's of Stress on Magnetic Flux Leakage and Magnetic Barkhausen Noise Signals

Pipelines are pressure vessels. Their enviable safety record compares weil with other transportation modes. Typical pipeline fatality rates are about 1% those of rail or air which are, in turn, about 1% of highway fatalities. Pipeline safety is first assured by rigorous inspection during pipe manufacture and line construction. All welds are inspected using radiography to detect voids and ultras...