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Abstract Magnetic cooling technology based on the magneto-caloric effect (MCE) has emerged as a viable alternative to conventional vapor compression refrigeration technology. Exploring suitable magnetic solids with promising magneto-caloric performances is a key issue in this field. Here, we report a systematic characterization of the glass forming ability, microstructure, magnetism and MCE of Ho 57 Cu 25 Al 18 and Tm 57 Cu 25 Al 18 amorphous ribbons. Promising MCE performances were observed for both ribbons at low temperature. Compared with most of the rare earth-based amorphous alloys, both ribbons were found to have comparable or even larger values of -Δ S M max (maximum magnetic entropy change), RC (refrigeration capacity) and RCP (relative cooling power). These promising magneto-caloric performances make amorphousized RE 57 Cu 25 Al 18 ribbons attractive for active cryogenic magnetic refrigeration. Highlights • Magnetism and magnetocaloric effect (MCE) in RE 57 Cu 25 Al 18 ribbons were studied. • Promising MCE performance was observed in amorphous RE 57 Cu 25 Al 18 ribbons. • The origin of MCE in amorphous RE 57 Cu 25 Al 18 ribbons was discussed. [ABSTRACT FROM AUTHOR]

The magnetic properties and magnetic entropy change of amorphousized Tm 60 Co 20 Ni 20 ribbon were systematically studied. The results indicate that the Tm 60 Co 20 Ni 20 amorphous ribbon reveals a second order magnetic transition (paramagnetic to ferromagnetic state) based on the Arrott plots and rescaled magnetic entropy change curves. A large magnetic entropy change is achieved around its Curie temperature of T C ∼6.7 K. Under the magnetic field change (Δ Η ) of 0–5 T, the maximum values of magnetic entropy change (−Δ S M max ) and relative cooling power ( RCP ) are 17.1 J/kg K and 273 J/kg, respectively. In particular, under a relative low Δ Η of 0–2 T, a large magnetic entropy change of 11.8 J/kg K reaches, making it attractive in the field of low-temperature magnetic refrigeration. [ABSTRACT FROM AUTHOR]

The magnetic properties and magnetocaloric effect (MCE) in Dy 2 Cu 2 In compound have been investigated. Dy 2 Cu 2 In undergoes two magnetic phase transitions, a paramagnetic to ferromagnetic (FM) at T C ∼ 49.5 K followed by a spin reorientation (SR) at T SR ∼ 19.5 K. For a magnetic field change of 0–7 T, the maximum values of the magnetic entropy change (−Δ S M max ) are estimated to be 16.5 around T C and 6.7 J/kg K around T SR with a large relative cooling power ( RCP ) value of 617 J/kg. The modified Arrott plots and universal curves of the rescaled Δ S M confirmed that the magnetic phase transitions in Dy 2 Cu 2 In compound belongs the second order phase transitions. The present results may provide some clues to search for new magnetocaloric materials belonging to RE 2 T 2 X system. [ABSTRACT FROM AUTHOR]

We present a detailed investigation of the crystal structure, magnetism and magneto-caloric performances of RE Co 2 B 2 C (RE = Gd, Tb and Dy) compounds. All compounds are described with a LuNi 2 B 2 C-type crystallographic structure (I 4/ mmm space group). A second-ordered paramagnetic to ferromagnetic (PM-FM) transition is observed in RE Co 2 B 2 C compounds around their Curie temperatures (T C) of 17.2, 5.3 and 7.7 K, and induced a considerable magneto-caloric effect (MCE) for GdCo 2 B 2 C, TbCo 2 B 2 C and DyCo 2 B 2 C, respectively. The magneto-caloric performances for RE Co 2 B 2 C were characterized by the isothermal magnetic entropy (- Δ S M max) , temperature averaged entropy change (TEC) with three different temperature lifts (3, 5 and 10 K), and relative cooling power (RCP). The corresponding values of - Δ S M max , TEC (3 K) and RCP under the magnetic field change (Δ H) of 0–5 T, are 10.34 J/kg-K, 10.23 J/kg-K, and 238.1 J/kg for GdCo 2 B 2 C, 18.09 J/kg-K, 17.83 J/kg-K, and 438.2 J/kg for TbCo 2 B 2 C, as well as 17.79 J/kg-K, 17.72 J/kg-K, and 480.1 J/kg for DyCo 2 B 2 C, respectively. • Magnetic properties and MCE in RE Co 2 B 2 C compounds were studied. • Large values of -ΔS M max, TEC, RC and RCP were observed at low temperature. • RE Co 2 B 2 C compounds are competitive for cryogenic magnetic cooling. [ABSTRACT FROM AUTHOR]

The magnetic refrigeration (MR) by utilizing the magnetocaloric effect (MCE) of magnetic solids has been considered a promising, environmentally benign, energy-efficient cooling technology. However, the lack of promising magnetic substances has slowed the development of its active application. To identify suitable candidate materials, we herein identified the structural and magnetic properties together with the MCE and magnetocaloric performances of rare earth (RE) rich RE 6 Ni 2.25 Al 0.75 (RE = Dy, Ho and Er) compounds. All the RE 6 Ni 2.25 Al 0.75 compounds are confirmed to crystallized in orthogonal Ho 6 Co 2 Ga-type structure and underwent paramagnetic to antiferromagnetic magnetic transitions. Moreover, large direct (conventional) and inverse MCEs have been observed in all the RE 6 Ni 2.25 Al 0.75 compounds. The values of peak magnetic entropy changes, temperature-averaged magnetic entropy changes with 5 K-lift and relative cooling powers under magnetic field change of 0–7 T are evaluated to be − 4.44 J/kg-K, − 4.38 J/kg-K and 230.6 J/kg for Dy 6 Ni 2.25 Al 0.75 , to be − 12.68 J/kg-K, − 12.26 J/kg-K and 378.2 J/kg for Ho 6 Ni 2.25 Al 0.75 , and to be − 17.52 J/kg-K, − 17.33 J/kg-K and 465.7 J/kg for Er 6 Ni 2.25 Al 0.75 , respectively. • The RE6Ni2.25Al0.75 (RE = Dy, Ho and Er) compounds are fabricated. • The structural and magnetic properties were investigated. • Large direct and inverse magnetocaloric effects were observed. • The Er6Ni2.25Al0.75 is considerable for cryogenic magnetic refrigeration. [ABSTRACT FROM AUTHOR]