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Abstract It is well known that rare earth (RE) based intermetallic compounds reveal various interesting magnetic properties depending on the crystallized structures and the constituent elements, paving the way for potential applications in different fields. Recent progresses regarding magnetic properties and magnetocaloric effect (MCE) in ternary rare earth RE 2 T 2 X (RE = Gd-Tm; T = Cu, Ni, Co; and X = Cd, In, Ga, Sn, Al) intermetallic compounds are reviewed in this paper. Some of them exhibit excellent MCE performances which make them attractive in the field of magnetic refrigeration at low temperature. With the aim of understanding the magnetocaloric characteristics of RE 2 T 2 X compounds, the crystal structure, magnetism and magnetic phase transition are also focused. The origin of the MCE together with the physics behind and the potential application of RE 2 T 2 X compounds are thoroughly considered. Highlights • Magnetic and magnetocaloric properties in RE 2 T2X compounds are reviewed. • The RE 2 T2X compounds show four types of crystallize structures. • Some of them exhibit excellent cryogenic magnetocaloric performances. • The origin of magnetocaloric effect in RE 2 T2X compounds is discussed. [ABSTRACT FROM AUTHOR]

The structure, magnetic transition and magnetocaloric properties in the ternary gallium intermetallic compounds of Ho 2 Ni 2 Ga and Tm 2 Ni 2 Ga have been systematically investigated by using X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and magnetization measurements. As found from powder XRD and Rietveld refinement, Ho 2 Ni 2 Ga and Tm 2 Ni 2 Ga crystallized in an orthorhombic structure of the W 2 B 2 Co type belonging to the Immm space group. Both compounds are ordering antiferromagnetically at low temperatures and under low magnetic fields together with a field-induced metamagnetic transition from antiferromagnetic (AFM) to ferromagnetic (FM). Peculiar and similar magnetocaloric properties are observed for both compounds, i. e., an inverse magnetocaloric effect (positive magnetic entropy change, Δ S M ) under low magnetic field changes (Δ H ) and at low temperatures together with a large normal reversible magnetocaloric effect under high Δ H . The positive Δ S M below/at the Néel temperatures ( T N ) is ascribed to first order transition from antiferromagnetic (AFM) to ferromagnetic (FM) states, whereas the negative Δ S M above T N is due to the fact of the magnetic transition from paramagnetic (PM) to ferromagnetic (FM) states. Based on the field-dependent magnetization data, the maximum magnetic entropy change (−Δ S M max ), relative cooling power ( RCP ) and refrigerant capacity ( RC ) are established, and the corresponding values are 9.6 J/kg K, 276 J/kg and 206 J/kg for Ho 2 Ni 2 Ga, and are 4.3 J/kg K, 60 J/kg and 46 J/kg for Tm 2 Ni 2 Ga, respectively, for a magnetic field change of 0–70 kOe. [ABSTRACT FROM AUTHOR]

The magnetic properties, magnetocaloric effect (MCE) and universal behaviour of ternary Cadmium compounds Gd 2 Cu 2 Cd and Er 2 Cu 2 Cd have been investigated systematically. A second order magnetic phase transition from a paramagnetic to ferromagnetic state is observed for Gd 2 Cu 2 Cd and Er 2 Cu 2 Cd at their own Curie temperatures of T C ∼120 and 36 K, respectively. A large reversible MCE occurs near its own T C for both compounds. The maximum values of magnetic entropy change (−Δ S M max ) are 10.1 and 19.1 J/kg K under a magnetic field change of 0–7 T with no obviously hysteresis loss for Gd 2 Cu 2 Cd and Er 2 Cu 2 Cd, respectively. The corresponding values of refrigerant capacity ( RC ) and relative cooling power ( RCP ) are evaluated to be 386 and 373 J/kg, and to be 525 and 489 J/kg, respectively. The rescaled magnetic entropy change curves collapse onto a single curve for various magnetic fields, further confirming the Gd 2 Cu 2 Cd and Er 2 Cu 2 Cd compounds with the second order phase transition. [ABSTRACT FROM AUTHOR]

The magnetic and magnetocaloric properties in the equiatomic intermetallic compounds of TmZnAl and TmAgAl have been investigated. The compounds undergo a second order magnetic transition from paramagnetic to ferromagnetic state around its own Curie temperatures T C ∼2.8 K and 3.3 K for TmZnAl and TmAgAl, respectively. A considerable reversible magnetocaloric effect (MCE) was observed at low temperature. For a magnetic field change of 7 T, the maximum values of magnetic entropy change (−Δ S M max ) and relative cooling power ( RCP ) are 11.8 J/kg K and 289 J/kg for TmZnAl, respectively, and the corresponding values for TmAgAl are 14.1 J/kg K and 315 J/kg. [ABSTRACT FROM AUTHOR]

Magnetic properties and magnetocaloric effect (MCE) in ErFeAl and HoFeAl intermetallic compounds have been studied systematically. Both compounds undergo a second order magnetic phase transition from paramagnetic to ferromagnetic state together with a probable spin reorientation transition at low temperature. A considerable reversible magnetocaloric effect was observed around its own Curie temperatures T C ∼55 K and 80 K for ErFeAl and HoFeAl, respectively. For a magnetic field change of 0–7 T, the maximum values of magnetic entropy change (−Δ S M max ) are found to be 8.3 and 9.9 J/kg K for RE = Er and Ho, respectively. The corresponding values of refrigerant capacity ( RC ) are evaluated to be 384 and 647 J/kg. [ABSTRACT FROM AUTHOR]