Complex Permeability After-Effect and Analysis of Power Losses in Ferromagnetic Co-Based Amorphous Alloy

J. Kravčák Department of Physics, FEI, Technical University of Košice, Park Komenského 2, 042 00 Košice R. Varga and P. Vojtaník Institute of Physics, P.J. Šafá rik University, Park Angelinum 9, 041 54 Košice, Slovakia

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Received: 9 07 2007;

Complex permeability (μ= μ1-iμ2) after-effect of near-zero magnetostrictive CoFeCrSiB amorphous alloy was investigated in magnetic field H (t)= H0exp(i2πft) after demagnetization. For frequencies f from 200 Hz to 2000 Hz and for the small amplitude H0 < Hcr we observed practically constant both real μ1 and imaginary part μ2 of permeability. A measured small decrease in the real part μ1 and increase in the imaginary part μ2 with frequency f were theoretically calculated for a quadratic form of a domain wall potential ES(x)=1/2 α x2. The calculated loss factortan δ= μ2 μ1, which is small at amplitude H0<Hcr, corresponds to power losses due to eddy currents induced around reversibly moving domain walls.

DOI: 10.12693/APhysPolA.113.43 PACS numbers: 75.40.Gb, 75.60.Ch, 75.60.Lr