BARKHAUSEN-NOISE AND MECHANICAL SENSITIVITY IN FINEMET-TYPE MATERIALS

Gergely Eszenyi – Sándor Szabó – Lajos Harasztosi – Ferenc Zámborszky
– József Nyéki -Zoltán Erdélyi – Dezső L. Beke

   Measuring technique, developed at our Laboratory for the investigation of ferromagnetic industrial materials, experimental results obtained and their analysis are reviewed. The magnetic properties (permeability, mechanical sensitivity) of as received and heat treated Finemet type ribbons (Fe₇₅Si₁₅NbBCu) were measured with common industrial equipments. The above properties were correlated with magnetic Barkhausen noise parameters. The distributions of peak area A and peak noise energy E were analyzed and it was found that distribution of the noise parameters PP(x) (where x = A or E), were in good agreement with the theory of self organized criticality (SOC), satisfying power laws in the form P(x) ~ x^-β. Useful correlation between the noise parameters and the mechanical sensitivity has been established. The noise did not considerably depend on the other parameters of ribbons.

Keywords: Barkhausen noise measurement, mechanical sensitivity, finemet-type alloys

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