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The rare-earth (RE)-based magnetic solids with large magneto-caloric effect (MCE) have been well investigated recently due to their potential applications in the field of environmentally friendly cryogenic magnetic refrigeration (MR). Herein, two polycrystalline RE-based REFe2Si2 (RE = Dy and Tb) intermetallic compounds have been prepared by an arc-melting way and determined with regard to the structural and magnetic phase transition (MPT) properties as well as the MCE and magneto-caloric performance. Both of the present REFe2Si2 compounds at room temperature are crystallized in a ThCr2Si2-type structure and undergo a first-ordered MPT from antiferromagnetic to paramagnetic state around the Néel temperature (TN) of ~ 4.05 K for DyFe2Si2 and ~ 6.25 K for TbFe2Si2, respectively. Large cryogenic MC effect together with excellent MC performance have been realized in DyFe2Si2 compound. The MC parameters with magnetic field change at 0–5 T of the maximum magnetic entropy changes and the refrigerant capacity/relative cooling power were found to be 16.08 J/kgK and 318.5/403.3 J/kg for DyFe2Si2 and to be 9.88 J/kgK and 105.9/140.8 J/kg for TbFe2Si2, respectively. [ABSTRACT FROM AUTHOR]

Reported here is a systematical investigation on the crystal structure, magnetic properties and magnetocaloric (MC) effect of three rare earth (RE) molybdate RE 2 MoO 6 (RE = Dy, Tb and Gd) oxides. The X-ray powder diffraction and the morphology as examined using the scanning electron microscope indicate phase-pure and polycrystalline nature of these oxides. The temperature (2–100 K) and magnetic field (up to 5 T) dependence of the magnetic measurements determine the magnetic phase transition (MPT) and MC properties. All the present RE 2 MoO 6 oxides crystallize in a monoclinic structure belonging to C 2/ c space group with the antiferromagnetic ordering at low temperature. Moreover, the RE 2 MoO 6 oxides hold reasonable values of MC parameters including the maximum isothermal magnetic entropy change/temperature-averaged entropy change (2 K lift) and relative cooling power values have been evaluated with the magnetic change of 0–5 T, yielding 17.22 (17.08) J/kgK and 277.67 J/kg for Dy 2 MoO 6 , 17.03 (16.83) J/kgK and 261.12 J/kg for Tb 2 MoO 6 , as well as 27.68 (26.69) J/kgK and 228.14 J/kg for Gd 2 MoO 6 , respectively. These acceptable MC parameters make the present RE 2 MoO 6 oxides potential candidates for cryogenic magnetic refrigeration (MR). [ABSTRACT FROM AUTHOR]

Magnetic cooling (MC) by utilizing the magnetocaloric effect (MCE) has been considered as one of the most potential promising solid state alternative method to present well-used state-of-the-art gas compression cooling technique. In this work, the rare earth (RE)-rich indides Gd 6 Co 2.2 In 0.8 , Tb 6 Co 2.2 In 0.8 , Dy 6 Co 2.2 In 0.8 and Ho 6 Co 2.2 In 0.8 were fabricated and checked with respect to their crystal structure, magnetic properties and magnetocaloric performances. All the RE 6 Co 2.2 In 0.8 samples are crystallized with the orthorhombic Ho 6 Co 2 Ga-type structure and ordered magnetically. Considerable cryogenic magnetocaloric performances have been found. Around the magnetic transition temperatures of 76, 32, 50 and 18 K for Gd 6 Co 2.2 In 0.8 , Tb 6 Co 2.2 In 0.8 , Dy 6 Co 2.2 In 0.8 and Ho 6 Co 2.2 In 0.8 , the magnetic entropy change (Δ S M) peak values with a magnetic change (Δ H) equals to 0–70 kOe and the corresponding temperature averaged Δ S M (with 3 K-lift) are 11.84 and 11.82 J/kg-K, 8.96 and 8.80 J/kg-K, 9.59 and 9.54 J/kg-K, 20.83 and 20.38 J/kg-K for Gd 6 Co 2.2 In 0.8 , Tb 6 Co 2.2 In 0.8 , Dy 6 Co 2.2 In 0.8 and Ho 6 Co 2.2 In 0.8 , respectively. • The RE 6 Co 2.2 In 0.8 (RE = Gd, Tb, Dy, Ho) compounds are fabricated. • Magnetic properties and MCE in RE 6 Co 2.2 In 0.8 compounds were studied. • Considerable MCE parameters were observed at low temperature. [ABSTRACT FROM AUTHOR]

Nowadays, the rare earths (RE) based magnetic materials with various promising functional characterizations are playing particularly important roles in present modern society and daily life. The magnetocaloric (MC) effect which is the basis of solid state magnetic refrigeration (MR) technology has been extensively investigated in various magnetic materials. In this work, a series of high quality RE -based RE 2 BaZnO 5 (RE = Gd, Dy, Ho, and Er) compounds have been fabricated and a combination of theoretical and experimental investigation has been performed in terms of the crystal structure, electronic structure, magnetic properties and magnetic phase transition (MPT) as well as the MC effects and MC performance. All the RE 2 BaZnO 5 compounds are confirmed to crystallize in the orthorhombic structure belonging to Pnma space group and with a typical semi-conductor characteristic. Based on the magnetization measurements and the first principle calculations, all the RE 2 BaZnO 5 compounds are ordering magnetically below 3 K and the ground state is of a ferromagnetic (FM) ordering for RE = Dy or Ho, whereas is of an antiferromagnetic (AFM) ordering for RE = Gd or Er, respectively. Additionally, considerable MC effects have been observed for all the RE 2 BaZnO 5 compounds which are related to the first ordered MPT for RE = Gd or Er, whereas related to the second order MPT for RE = Dy or Ho, respectively. Moreover, considerable MC effects and promising MC performance have been realized in the present RE 2 BaZnO 5 compounds, especially for the Dy 2 BaZnO 5 and Ho 2 BaZnO 5 , making them considerable for cryogenic MR applications. [Display omitted] [ABSTRACT FROM AUTHOR]

The rare-earths (RE) based materials with large magnetocaloric effect (MCE) have been recently recognized as potential candidates for practical solid-state magnetic refrigeration. In this work, the two light RE -based ternary RE Cu 2 Si 2 (RE = Nd and Pr) compounds were fabricated by arc-melting method and investigated the structural, magnetic and magnetocaloric properties. Both RE Cu 2 Si 2 compounds are found to crystallize in a ThCr 2 Si 2 -type layered crystal structure with the I 4/ mmm space group and undergo a field-induced first-ordered magnetic transition (MT) around 13.6 and 3.5 K for NdCu 2 Si 2 and PrCu 2 Si 2 , respectively. Large reversible MCE has been observed in both RE Cu 2 Si 2 compounds, and the magnetocaloric parameters of the maximum isothermal magnetic entropy change (-Δ S M max) and relative cooling power (RCP) with the magnetic field change (Δ H) of 0–7 T are determined to be 5.9 J/kg-K and 82.6 J/kg for NdCu 2 Si 2 compound and to be 8.0 J/kg-K and 67.2 J/kg for PrCu 2 Si 2 compound, respectively. • The ternary RE Cu 2 Si 2 (RE = Nd and Pr) compounds are synthesized. • Cryogenic magnetic properties in RE Cu 2 Si 2 were studied. • The magnetocaloric parameters in RE Cu 2 Si 2 compounds were determined. [ABSTRACT FROM AUTHOR]

The magnetic refrigeration (MR) technology by utilizing the magnetocaloric (MC) effects of magnetic solids have been realized to be a promising energy efficiency and environmentally friendly technology. Developing or discovering proper magnetic solids with promising MC performances is one of the most important tasks at present stage since a huge gap still exists between the requirement of practical MR application and the MC performances of the magnetic solids. Herein, we reported a combined theoretical and experimental investigation of the crystal structure together with the magnetic properties, magnetic phase transition (MPT) and MC performances in Gd 2 MgTiO 6 oxide. The Gd 2 MgTiO 6 is confirmed to crystalize in a B -site ordered monoclinic double perovskite (DP) crystal structure. A rather unstable antiferromagnetic (AFM) interaction with large magnetic moment and semi-conductor characteristic with the band gap of 2.977 eV have been confirmed in Gd 2 TiMgO 6 DP oxide at ground state. Giant reversible cryogenic MC effect together with excellent MC performances have been confirmed by a series of the figure of merits including the values of maximum magnetic entropy change (-Δ S M) and refrigerant capacity (RC), which are evaluated to be 46.21 J/kgK and 300.27 J/kg around 3.3 K with the magnetic change of 0–7 T, these values are much better than most of the recently reported famous cryogenic MC materials and the commercialized magnetic refrigerants gadolinium gallium garnet (GGG) as well. The observed excellent MC performances suggest that Gd 2 TiMgO 6 DP oxide is a promising candidate material for cryogenic MR applications. Graphical abstract [Display omitted]. [ABSTRACT FROM AUTHOR]

• The quaternary RE Cr 2 Si 2 C (RE = Gd, Tb, Dy) compounds are fabricated. • The structural, magnetic, MTP and MC properties in RE Cr 2 Si 2 C were studied. • The GdCr 2 Si 2 C compound is considerable for cryogenic magnetic refrigeration. The rare earths (RE) based materials with large reversible magnetocaloric effects have been recently recognized as good candidates for practical cryogenic magnetic refrigeration. In this work, three RE -based quaternary silicon carbides of RE Cr 2 Si 2 C (RE = Gd, Tb, Dy) were synthesized and determined the crystal structure, magnetic properties, magnetic phase transition, and magnetocaloric performances. All RE Cr 2 Si 2 C compounds are crystallized in the carbon-filled CeMg 2 Si 2 -type crystal structure and revealed a second-order magnetic phase transition from ferromagnetic to paramagnetic without noticeable field or thermal hysteresis around the Curie temperatures (~10.9 K for GdCr 2 Si 2 C, ~16.6 K for TbCr 2 Si 2 C, and ~10.7 K for DyCr 2 Si 2 C). The magnetocaloric parameters including the maximum magnetic entropy change, temperature-averaged entropy changes with 3 K lift, as well as refrigerant capacity/relative cooling power are applied to determine the magnetocaloric performances, and the evaluated values are 21.7, 14.6 and 9.8 J/kgK, 20.97, 14.51, and 9.73 J/kgK, as well as 248.3/328.8, 302.8/393.8, and 211.3/274.9 J/kg for GdCr 2 Si 2 C, TbCr 2 Si 2 C, and DyCr 2 Si 2 C under the field change of 0–50 kOe. These results indicate that the GdCr 2 Si 2 C possesses promising magnetocaloric performances and is considerable for cryogenic magnetic refrigeration application. [ABSTRACT FROM AUTHOR]