Soft magnetic properties enhancement effect and crystallization processes in Fe78−xNbxSi13B9 (, 2, 4) amorphous alloys

Optimization of soft magnetic properties and crystallization in FeAgNbSiB, FeAgNbB and FeAgCoNbB amorphous alloys

“…Indeed, such a conclusion is confirmed by our results. Comparing the Curie temperature for the Fe 75.75 Ag 0.25 Nb 2 Si 13 B 9 , Fe 75.75 Ag 0.25 Nb 2 B 22 amorphous alloys with T c of the Fe 76 Nb 2 Si 13 B 9 and Fe 76 Nb 2 B 22 amorphous alloys studied in [23,30] one can conclude that the presence of silver causes a decrease of T c by about 10 and 14 K, respectively. Taking into account the alloys Fe 80 Nb 2 B 18 studied in [30] and the Fe 74.75 Ag 0.25 Co 5 Nb 2 B 18 alloy one can conclude that Co atoms causes an increase of the Curie temperature.…”

“…The influence of silver atoms on the temperature of the first stage of crystallization is similar which also was discussed in [33,34] for FeAgSiB alloys. For example T x1 for the Fe 75.75 Ag 0.25 Nb 2 Si 13 B 9 alloy in relation to the Fe 76 Nb 2 Si 13 B 9 alloy [23] is lower by about 40 K.…”

“…Indeed as it was shown in [21][22][23][24][25][26][27] a significant increase of permeability observed in samples free of iron nanograins was attributed to annealing out of free volume and a reduction of internal stresses, i.e. to the so-called relaxed amorphous phase.…”

Structural Relaxation in Fe78Nb2B20Amorphous Alloy Studied by Mössbauer Spectroscopy

“…2 allow concluding that the observed optimization effect cannot be attributed to iron nanostructure. The significant increase of permeability is due to annealing out of free volume and a reduction of internal stresses, as it was discussed in [6][7][8][9][10][11][12].…”

“…Such a microstructure averages out magnetic anisotropy and gives an enhancement of magnetic permeability. However, as it was shown at first time in [6] in some alloys the optimization effect can be observed without formation of iron nanograins and can be attributed to annealing out of free volume (frozen into material during fabrication) and a reduction of internal stresses [6][7][8][9][10][11][12]. This effect is especially interesting because it allows obtaining very good soft magnets free of embrittlement -the main disadvantage -of nanostructured magnets.…”