Thermal stability and saturation magnetization of a new series of amorphous Fe80−xCoxP14B6 (20≤x≤40) alloys

Magnetic properties of Fe–Co-based bulk metallic glasses

“…Concerning the M 10 kOe behavior as a function of Co content, the values measured in both samples geometry (see Table 1) indicate that the highest value has been measured in the composition having x = 0.2: a slight reduction in M 10 kOe is indeed observed for x = 0.4. It is noteworthy that this compositional dependence of the saturation magnetization it has been already observed in amorphous (Fe 1−x Co x ) 85 B 15 alloys [12,13] in which the maximum in the value of M s was observed for (Fe 75 Co 25 ) 85 B 15 composition. This behavior has been related to chemical short-range ordering in the amorphous structure observed by changes in the structure of the Mössbauer spectra [14].…”

Thermal stability of amorphous structure and magnetic properties Fe80–xCoxP14B6 (x = 20–40) ribbons

“…1 that the T C values of the amorphous FeCo-based alloys are substantially higher (150-250 K) than that of amorphous Fe 40 Ni 40 P 14 B 6 melt-spun ribbon produced under the same processing conditions. It means that the replacement of Ni by Co in the amorphous Fe-Ni-P-B alloys results not only in the enhancement of both the saturation magnetization and thermal stability of glassy structure [11], but also increases the stability of the ferromagnetic properties at elevated temperatures. It is worth noting that the Curie temperature of the Fe 40 Ni 40 P 14 B 6 metallic glass determined from our measurements (T C = 520 K) is in a good agreement with the value for this alloy reported in paper [13].…”

“…The amorphous state of alloys containing 30-35 at% Co lose their ferromagnetic properties in the supercooled liquid state (i.e. close to the range between T g and T ons temperatures), while the Fe 40 Co 40 P 14 B 6 alloy undergoes expected transition into the paramagnetic state during crystallization (α-(FeCo) solid solution + (FeNi) 3 (PB) intermetallic compound [11]). It is therefore impossible directly [8] glasses in which the replacement of Fe by Co leads to an increase in the Curie temperature.…”

“…In the majority of amorphous alloys, partial replacement of Fe by Co results in enhancement of the saturation magnetization (e.g. [3][4][5][6] Recently, a new series of amorphous Fe 80-x Co x P 14 B 6 (20 ≤ x ≤ 40) alloys has been reported with enhanced both the saturation magnetization (above 1.4 T) and thermal stability [11]. In this paper, the effect of the substitution of Fe by Co on the Curie temperature of the Fe 80-x Co x P 14 B 6 metallic glasses is reported and a comparison with the relevant literature data is presented.…”

High thermal stability of soft magnetic (Fe,Co)–Mo–B–C–P–Si metallic glasses

“…In another study [10], a presumably more stable glassy alloy, Fe 75 Mo 2 Ga 3 P 10 C 4 B 4 Si 2 with a larger T x ∼ 60 K, was found to devitrify into a metastable (Fe,Mo) 23 (B,C) 6 crystalline phase upon annealing at 0.37 T x above T g for 600 s. The metastable phase decomposed into ␣-(Fe,Mo) and other iron-metalloid phases when annealed above the crystallization temperature. The effect of cobalt substitution on thermal stability has also remained an area of interest in the Fe,Co-based metallic glasses [11,12]. In the present paper, a systematic study of the thermal stability of (Fe,Co)-Mo-B-C-P-Si metallic glasses with varying metalloid concentrations is performed by annealing the samples at temperatures inside the SCL region.…”