Magnetic entropy change and refrigerant capacity of rapidly solidified TbNi2 alloy ribbons

Abstract

The magnetocaloric effect in TbNi2 alloy ribbons synthesized by rapid solidification was investigated. This material crystallizes in a superstructure of the cubic Laves phase structure type C15 (space group F-43m). The saturation magnetization and Curie temperature are MS = 134 ± 2 A m2 kg−1 and TC = 37 ± 1 K, respectively. For a magnetic field change of 5 T, the material shows a maximum magnetic entropy change |ΔSMpeak| = 13.9 J kg−1 K−1, with a full-width at half-maximum δTFWHM = 32 K, and a refrigerant capacity RC = 441 J kg−1. The RC value is similar to those reported for other magnetic refrigerants operating within the temperature range of 10-80 K. Finally, it is worth noting that the use of rapid solidification circumvents the necessity for long-term high-temperature homogenization processes normally needed with these RNi2 alloys.

Magnetocaloric effect in ErNi2 melt-spun ribbons

“…It is also worth mentioning that these values agree, within the expected uncertainty, with those of bulk polycrystalline alloys. This situation coincides to the previously found for as-solidified TbNi 2 ribbons, 19 and contrasts with the behavior of DyNi 2 20 and HoNi 2 21 ribbons, in which enhanced MC properties were obtained due to the favorable combination of texture effects along ribbon length (extrinsic feature) and the anisotropic behavior of magnetization (i.e., due to the angle between the magnetic field and easy magnetization direction). But it is consistent with the absence of preferential grain growth in the fabricated ribbon samples.…”

“…This fabrication technique has been successfully applied in recent years to synthesize the isostructural Laves phases RNi 2 with R = Tb, Dy, Ho). [19][20][21]…”

Enhanced magnetocaloric effect in rapidly solidified HoNi2 melt-spun ribbons

“…The results obtained are compared with those previously reported for bulk polycrystalline samples. This processing technique has been recently applied to fabricate ribbon samples of other Laves phases of the same family, such as TbNi 2 and DyNi 2 with R = Tb or Dy [15,16], with positive results.…”

Texture-induced enhancement of the magnetocaloric response in melt-spun DyNi2 ribbons

“…20 Until now, the DyNi 2 compound has been prepared using conventional melting techniques (arc or RF melting) followed by long-term annealing (from several days to a month) at temperatures between 723 and 1073 K. 12,15,18 Rapid solidification using the melt spinning technique has been effectively applied to produce different crystalline magnetocaloric materials, such as LaFe 13Àx Si x , 21 MnCoGe (Ref. 22) (MnFe) 2 (PGe), 23 Gd 5 (SiGeSn) 4 , 24 TbNi 2 , 25 and Ni-Mn-X Heusler alloys (X ¼ Sn, In, Ga), [26][27][28] In all of the above-mentioned cases, a single phase was found in the as-quenched alloy ribbons, or after a much shortened annealing compared to their bulk counterparts. Hence, the aim of the present investigation has been to study the phase constitution and MC behavior of DyNi 2 as-quenched (aq) ribbons; the results are compared with those obtained for bulk samples produced by conventional alloying techniques.…”