Phase structure and magnetic properties of Fe–Nb–B–Tb type of bulk nanocrystalline alloys

Ultra-high coercivity of (Fe 86− x Nb x B 14 ) 0.88 Tb 0.12 bulk nanocrystalline magnets

“…In fact, for Tb 14 Fe 79.6 B 6.4 nanocrystalline melt spun ribbons (thickness in the order of tens of lm), almost 8 T coercivity and a strong influence of the cooling rate on magnetic properties has been reported [13]. Despite this achievement, the form of strips narrows possible application down, as in many cases, bulk materials are required.…”

“…Recently, we have reported magnetic properties and magnetic hardening effect of (Fe 80 Nb 6 B 14 ) 1Àx Tb x (0.02 6 x 6 0.32) bulk nanocrystalline alloys prepared by the mold casting [14,15]. These studies indicated that the used preparation method may yield bulk magnetic nanocomposite alloys in the form of rods with a diameter d = 0.5 -2 mm.…”

Influence of Cooling Rate on Magnetic Properties of (Fe_{80}Nb_{6}B_{14})_{1-x}Tb_{x} Type of Bulk Nanocrystalline Alloys

“…From the obtained results one can determine some characteristic quantities such as (i) the coercive elds in plus and minus H values (H c+ , H c− ), (ii) saturation magnetization (M s+ ) and remanence (M r+ ) in I quarter and (iii) maximum energy product (|JH| max ), that are listed in Table. Note that for the alloy with 8 at.% of Tb and d = 0.5 mm the coercive eld reaches the value of 2.46 T and |JH| max = 77.2 kJ/m 3 . This means that the applied vacuum suction casting allows introduction of additional magnetic anisotropy that [4]. This means that within the alloy family and for some applications it is possible to reduce the necessary rare earth content.…”

“…Recently we have reported that the (Fe 80 Nb 6 B 14 ) 1−x Tb x bulk nanocrystalline series of alloys can be considered as high coercive materials [4]. It was shown (Mossbauer spectra, XRD) that the examined samples contain magnetically hard Tb 2 Fe 14 B and other soft TbFe 2 , α-Fe nanocrystalline pahses.…”

Phase Stability of (Fe_{80}Nb_{6}B_{14})_{0.9}Tb_{0.1} Bulk Nanocrystalline Magnet

“…In the eld of magnetism very interesting are Fe-Nb-B type of nanocrystalline alloys [3,4]. Recently we have reported that the (Fe 80 Nb 6 B 14 ) 1−x Tb x bulk nanocrystalline series of alloys can be considered as highly coercive materials [5,6]. It was shown ( 57 Fe Mossbauer spectrometry and XRD) that the examined samples contain magnetically hard Tb 2 Fe 14 B and other TbFe 2 , α-Fe soft phases, high Tb content the high contribution of TbFe 2 .…”