Magnetic and structural study of (Fe1−xCox)62 Nb8B30 bulk amorphous alloys

The electric and magnetic properties of rapidly quenched (Fe1−xCox)62Nb8B30 bulk metallic glasses were studied with x=0, 0.33 and 0.50. The Curie temperature in the amorphous state was found to be about 245 °C for the Co-free alloy, 290 °C for x=0.33 and 201 °C for x=0.50, while the crystallization temperature is varying within 15° only around 600 °C. The change in TC correlates with the change in Mössbauer parameters. An interesting flattening effect of annealing on the hysteresis loop was observed which increases with the Co content. The resistivity could not be improved above 152 μΩ cm, which limits the high frequency applications of these alloys.