Structure evolution and magnetic properties of annealed Fe77-x-yCuxNbySi13B10 alloys

The microstructure and magnetic properties of the amorphous and partially crystallized Fe77-x-yCuxNbySi13B10 (x=0 or 1 and y=0, 1, 2 or 3) ribbons were investigated. From Mössbauer spectroscopy investigations it was stated that the half linewidth in Zeeman sextets corresponding to very fine α-FeSi grains is larger than that observed in the crystalline alloys which is caused by the interface effect. Moreover, the off-plane anisotropy is observed after annealing the Fe75Cu1Nb1Si13B10 ribbon at 693 K. This may be attributed to the nucleation of α-FeSi grains in the ribbon surface. The excellent soft magnetic properties were obtained for the Fe-based nanocrystalline alloy with additives of 1 % Cu and 2 or 3% of Nb