Effects of field annealing on the magnetic characteristics and magnetic losses of amorphous ribbons Fe₇₈Si₁₀B₁₂

The effects of magnetic annealing on the magnetic characteristics and magnetic losses of amorphous ribbons Fe₇₈Si₁₀B₁₂ were studied. The annealing temperature was chosen at 400°C, being lower than the Curie temperature 440°C. A magnetic field of 30 Oe was applied during the heat treatment, in a direction at an angle θ to the length of the ribbon, with θ = 0°, 45°, 60°, 90°. The magnetic characteristics in ac fields were measured with the frequencies from 50 Hz to 10 kHz. The total losses W were measured and resolved into the hysteresis loss W_h, the classical eddy current loss W_e, and the anomalous eddy current loss W_ea. In general, at a given frequency and a given maximum induction, W_ea decreases and W_h increases with the direction θ. So the optimum annealing conditions for lowest total loss are different for different frequency and maximum induction.