Magnetic properties of nanocrystalline Finemet alloys with Co addition

This report focuses on ac magnetic properties of (Fe0.5Co0.5)73.5Cu1Nb3Si13.5B9 alloy in the high temperature. The effects of replacing 50% Fe by Co in Fe73.5Cu1Nb3Si13.5B9 alloy on the static magnetic properties have also been studied. Addition of Co leads to an increase around 110 K of the Curie temperature of the amorphous phase, much higher than Ge-containing Finemet alloy. The material has much better ac magnetic properties than Hitperm alloy. An excellent stability of initial permeability in high temperature (up to 650 K) and high frequency (up to 5 × 105 Hz) can be observed with respect to the Co-free alloy.