Optimisation of soft magnetic properties in Fe–Cu–X–Si13B9 (X=Cr, Mo, Zr) amorphous alloys

The Mössbauer Study of Magnetic-permeability-enhancement Effect in the Fe86-xNbxB14(x=5, 6) Amorphous Alloys

“…The great interest in the recent years is devoted to the nanocrystalline alloys obtained by annealing of the amorphous-based alloys at temperatures close to the crystallization temperature [1][2][3][4][5][6][7]. Softer magnetic materials consist of Fe-rich nanocrystallites embedded in a soft amorphous matrix.…”

“…According to the random anisotropy model [1][2][3][4][5] such a structure with randomly oriented nanocrystallite grains of dimension (typically 10-15 nm) much smaller than the ferromagnetic exchange length gives an averaging out of magnetic anisotropy and leads to an enhancement of soft magnetic properties. Because metallic glasses exhibit considerable variation of their material properties with thermal annealing at temperatures below the crystallization temperature, another mechanism attributed to structural relaxation occurring in the glassy state was also proposed [7,8]. The possible atomic-rearrangement events associated with structural relaxation can be classified as the following: (i) a change in the mean near-neighbor distance, (ii) a change in the mean chemical order, and (iii) a change in the mean coordination number.…”

Magnetic properties of amorphous and nanocrystalline alloys based on iron

“…The characteristic temperatures T c , T op and T 1 are listed in Table 1. In this table, for comparison, we also list the data obtained for similar amorphous alloys in [17]. …”

“…(5) is able to describe all three processes leading to the discussed enhancement of magnetic permeability as well as thermal instability of an amorphous alloy due to the presence of microvoids. From these processes surely formation of a nanocrystalline phase is the most effective because of the dependence 1/µ ∝ D 6 , but the other two also in some cases should play an important role like in the case of Fe 78 Si 13 B 9 alloy [17] or Fe 74 Cu 1 Cr 3 Si 13 B 9 alloy. From Eqs.…”

“…The influence of alloying addition on optimisation processes for similar amorphous alloys (listed in Table 1) has been studied in [17]. In this paper for studying the kinetic of the formation of ␣-Fe(Si) nanocrystalline phase the resistometric method also has been used.…”