Magnetic and crystallization behavior of Be-substituted Fe82B18 metallic glasses

Abstract

Substitution of Be for B in the amorphous binary alloy Fe82B18 was observed to cause an initial increase in saturation magnetization (Ms) to a maximum of 200 emu/g at 4.2K, followed by a decrease for alloys with more than 4 at.% Be. Meanwhile, the Curie temperature of the Fe82B18−y Bey alloys decreased progressively with the Be content. These changes in Ms and TC differ from those observed in the Fe-B-M′ metallic glasses, where M′ is another metalloid (P, C, Si or Ge). Results from Auger electron spectroscopy and Mössbauer experiments confirmed the reversal trend detected in the magnetization measurements. Combining all these results enables us to attribute the initial increase in Ms to a smaller charge transfer from the Be atoms than that from the B atoms to Fe and the subsequent decrease in Ms to a possible clustering of the Be atoms at higher concentrations. The annealing behavior for the present alloys is described in terms of crystallization stages and the phases formed.

Probing the Electronic Structure of Metallic Glasses using AugerXVVTransitions

“…The amorphous ternary system Fe^B^^Be^ was chosen for study because the alloys with x up to six, i.e., 6 at.% Be, exhibited an anomalous peak in ]I Fe between 4 and 5 at.% Be. 3 Our appli-cation of AES to the amorphous Fe-B-Be alloys thus had the additional incentive to confirm this puzzling magnetic behavior besides the purpose aforementioned.…”

Effect of Si on the glass-forming ability, thermal stability and magnetic properties of Fe–Co–Zr–Mo–W–B alloys

“…This parallelism also holds in Fe 80 Be x B 20−x glasses [20]. Furthermore, the non-monotonic change of M RT and T c occurs in many Fe-based glasses [21,22].…”

“…The Curie temperature of fcc or hcp iron is about 300 K by extrapolating the data of Fe-B glasses, but that of b.c.c ␣-iron is higher up to 1050 K [11,21]. In addition, it is known that fcc ␥-iron has a small magnetic moment (∼0.1 B ) [26], but b.c.c ␣-iron has a larger magnetic moment (2.22 B ) at 0 K [29].…”