Amorphous Co-based alloy with low losses at high frequencies

On the basis of CoMn a new amorphous alloy with a saturation flux density B
s
= 0.8 T and very low magnetostriction λ
s
is presented. Tailored hysteresis loops and excellent magnetic properties can be obtained by a systematic variation of the cooling rate with and without a magnetic field. High permeabilities μ
a
at 50 Hz are found for round loops. For flat hysteresis loops, a constant permeability
\mu_{a}\approx 4000
up to about 1 MHz can be adjusted. The iron losses p
Fe
at 100 kHz at the same time, are very low and comparable to the classically calculated eddy current losses.