Magnetocaloric performance of the three-component Ho1-xErxNi2 (x = 0.25, 0.5, 0.75) Laves phases as composite refrigerants

Abstract

To date, significant efforts have been put into searching for materials with advanced magnetocaloric properties which show promise as refrigerants and permit realization of efficient cooling. The present study, by an example of Ho1−xErxNi2, develops the concept of magnetocaloric efficiency in the rare-earth Laves-phase compounds. Based on the magneto-thermodynamic properties, their potentiality as components of magnetocaloric composites is illustrated. The determined regularities in the behaviour of the heat capacity, magnetic entropy change, and adiabatic temperature change of the system substantiate reaching high magnetocaloric potentials in a desired temperature range. For the Ho1−xErxNi2 solid solutions, we simulate optimal molar ratios and construct the composites used in magnetic refrigerators performing an Ericsson cycle at low temperatures. The tailored magnetocaloric characteristics are designed and efficient procedures for their manufacturing are developed. Our calculations based on the real empirical data are very promising and open avenue to further experimental studies. Systems showing large magnetocaloric effect (MCE) at low temperatures are of importance due to their potential utilization in refrigeration for gas liquefaction.

Designing magnetocaloric materials for hydrogen liquefaction with light rare-earth Laves phases

“…This design strategy for designing the light rare-earth RAl 2 Laves phase series for magnetocaloric hydrogen liquefaction may be applied to other light rare-earth alloys to tailor their magnetocaloric effects for the liquefaction of industrial gases, inclusive but not limited to hydrogen gas. In addition, our work is also helpful for designing magnetocaloric composites, since tuning the Curie temperature in layered structures with a constant ∆S T over a wide temperature range is important for applications [60,62].…”

“…Mixing two different heavy rare-earth elements on the rare-earth sites is a widely used method. Examples are several works on heavy rare-earth Laves phases RNi 2 , RAl 2 , and RCo 2 (R: rare-earth element) systems: the Dy 1−x Er x Ni 2 (x = 0.25, 0.5, 0.75) [59], the Tb 1−x Er x Ni 2 (x = 0.75, 0.5, 0.25) [60], the Tb 1−x Ho x Ni 2 (x = 0.25, 0.5, 0.75) [61], the Ho 1−x Er x Ni 2 (x = 0.25, 0.5, 0.75) [62], the Tm x Dy 1−x Al 2 (0 ⩽ x ⩽ 1) [13], the (Er x R 1−x )Co 2 (R=Ho, Dy; 0 ⩽ x ⩽ 1) [63] and the Er x Dy 1−x Al 2 (x = 0.45, 0.67, 0.9) [64]. Following these studies, we apply this method to the light rare-earth Laves phases: mixing different light rare-earth elements on the rare-earth sites to tune the transition temperature within 20-77 K for magnetocaloric hydrogen liquefaction.…”

Structure, Microstructure and Magnetocaloric/Thermomagnetic Properties at the Early Sintering of MnFe(P,Si,B) Compounds

“…Compounds deriving from Fe 2 P such as MnFe(P,As) [17], MnFe(P,Si) [18] or MnFe(P,Si,B) [19] are also appealing as they combine giant magnetocaloric/thermomagnetic effects at their first-order ferromagnetic transition with a high tunability of the Curie temperature. Magnetocaloric applications can also be considered over an extended range of temperature; so, magnetocaloric properties have been systematically investigated in various other material systems, including oxides [20][21][22], transition metals, and rare earth intermetallic systems [23][24][25][26][27][28][29].…”

Large magnetic entropy change in Ni–Mn–In–Sb alloys via directional solidification and calculated by first-principles calculations

“…4 Extensive studies have been performed to obtain magnetic refrigeration materials with large isothermal magnetic entropy change (ΔS). Currently, the investigated magnetic refrigeration technology system mainly includes rare earth alloys, 5,6 perovskite, 7,8 and Heusler alloys. 9,10 Among these materials, Heusler alloys have received more attention and research studies due to the rich ferromagnetic (FM)/antiferromagnetic (AFM) martensitic transformations.…”

“…[11][12][13] Long et al prepared common Ni 55. 5 Mn 20 Ga 24.5 and Ni 54.9 Mn 20.5 Ga 24.6 polycrystalline alloys with ΔS of 15.1 and 13.1 J kg −1 K −1 , but their magnetocaloric effects are not ideal. This is because there are a large number of internal crystal defects (such as grain boundaries) in polycrystalline alloys, which will greatly reduce the degree of atomic ordering, following which the ΔS in polycrystalline alloys will be weakened.…”