Effect of B to Si concentration ratio on glass-forming ability and soft-magnetic properties in (Co0.705Fe0.045B0.25-xSix)(96)Nb-4 glassy alloys

The effect of B to Si concentration ratio on the glass-forming ability (GFA) and soft-magnetic properties of (Co0.705Fe0.045B0.25-xSix)(96)Nb-4 (x=0.02-0.1) alloys was investigated. The (Co0.705Fe0.045B0.25-xSix)(96)Nb-4 bulk glassy alloys with diameters up to 2 mm were synthesized in the composition range of x=0.02-0.06. In addition to high GFA, the Co-based glassy alloys exhibit excellent soft-magnetic properties as well, i.e., rather high saturation magnetization of 0.62 T, low coercive force of 0.6-1 A/m, and superhigh initial permeabilities of 37 100-53 700 at 1 kHz under a field of 1 A/m. The alloys with Si contents of x=0.05 and 0.06 exhibit high initial permeabilities of 29 300 and 24 300, respectively, even at 100 kHz. (c) 2007 American Institute of Physics