Structural relaxation, crystallization and improvement of magnetic properties effect in Fe–X–Si–B (, Zr, Al, V) alloys

Long-term stability of soft magnetic properties of amorphous and nanocrystalline alloys based on iron

“…The decrease of the value m(T op ) caused by 8 years aging does not exceed 3%. Indeed in this case the optimization annealing leads to formation of aFe(Si) nanograins with mean grain size in the range 5-20 nm (determined by applying high-resolution electron microscopy) [10][11][12]. So, one can conclude that after annealing at T op the alloy is at least in a partial thermodynamic equilibrium.…”

“…[5,7] magnetization in saturation measurements carried out with different heating rates) and (ii) the mechanism of the ESMP effect in these alloys examined in Refs. [5][6][7][8][9][10][11][12] for samples directly after annealing is quite different. Using the following experimental techniques-permeability measurements, resistivity, coercive field, magnetic balance, X-ray diffraction, Mo¨ssbauer spectroscopy and high-resolution electron microscopy-it was shown that for the two alloys, i.e.…”

Influence of boron content on crystallization and magnetic properties of ternary FeNbB amorphous alloys

“…Both processes, that is the crystallization and the optimization are controlled by diffusion thus they are thermally activated processes 17, 18. The fact that B as well as Nb cause an increase of the temperatures T x 1 and T op means that these elements in amorphous alloys based on iron cause a slowing down of diffusion processes.…”

“…4 and Table 1 it can be concluded that with increasing B content the 1‐h optimization annealing temperature increases. Structural examinations (X‐ray diffraction and high resolution electron microscopy) as well as magnetic and electric measurements show that the optimization annealing (at T op ) in the examined alloys leads to formation of the so‐called relaxed amorphous phase (annealing out of free volume) free of iron nanograins 17, 23. Intensity of the structural relaxation depends on alloying additions in this way that for elements with higher melting points free volume content frozen during fast quenching is smaller 17.…”

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

“…Because of some unique properties (very high magnetic permeability and also resistivity) these alloys have found nowadays industrial applications in the field of electrical engineering as magnet cores or different kind of sensors [1][2][3][4][5]. Moreover magnetic properties of amorphous alloys based on iron can be significantly improved by applying a specific thermal annealing [6][7][8][9]. The conditions of the socalled optimization annealing (i.e.…”