Structure transformation and elements redistribution at heating of Fe73.5Nb3Cu1Si13.5B9 amorphous alloy

Effect of the oxidation in the surface magnetic properties of as-quenched and relaxed Finemet alloy

“…1 the value of Curie temperature, T C , of the as-quenched sample is 330.97°C, which agrees with the magnitudes obtained for the Finemet with 3% of Nb concentration [12,13]. Thermal treatment at 400°C for 30 min results in an increase of T C of about 9°C.…”

On the effect of cooling rate during melt spinning of FINEMET ribbons

“…This will cause inhomogeneity in the composition of the surrounding amorphous phase and the formation of local areas with different T c . 27,32,33 As proposed previously, the faster diffusing B atoms in the amorphous phase have a smooth concentration prole while the large slower Nb atoms accumulate sharply at the nanocrystalline grain boundaries. Therefore, the higher T c could be ascribed to Nb-poor and B-rich interior regions and the lower T c of the amorphous phase is related to regions near the grain boundaries with a high concentration of Nb atoms.…”

Curie temperature behaviour at relaxation and nanocrystallization of Finemet alloys

“…This leads to inhomogeneity of composition in an amorphous structure, which in its turn results in formation of distribution of local areas in an amorphous phase with different Tc points. A decrease in the height of Tc peak correlates with a decrease in the amount of an amorphous phase by crystallization, as well as with lowering magnetostriction of the remaining amorphous phase [14].…”

“…It has been reported that annealing of an amorphous alloy up to starting a crystallization process may result in splitting the Tc calorimetric peak [13,14]. Growing crystals change the composition of a surrounding amorphous phase.…”

“…The apparent value of activation energy E of relaxation can be defined from the time-temperature dependencies using the following equation [14]:…”