Multicaloric Cryocooling Using Heavy Rare-Earth Free La(Fe,Si)₁₃-Based Compounds

The transition toward a carbon-neutral society based on renewable energies goes hand in hand with the availability of energy-efficient technologies. Here, magnetocaloric cooling is a very promising refrigeration technology to fulfill this role regarding cryogenic gas liquefaction. However, the current reliance on highly resource critical, heavy rare-earth-based compounds as magnetocaloric material makes global usage unsustainable. Here, we aim to mitigate this limitation through the utilization of a multicaloric cooling concept, which uses the external stimuli of isotropic pressure and magnetic field to tailor and induce magnetostructural phase transitions associated with large caloric effects. In this study, La_0.7Ce_0.3Fe_11.6Si_1.4 is used as a nontoxic, low-cost, low-criticality multiferroic material to explore the potential, challenges, and peculiarities of multicaloric cryocooling, achieving maximum isothermal entropy changes up to −28 J (kg K)⁻¹ in the temperature range from 190 K down to 30 K. Thus, the multicaloric cooling approach offers an additional degree of freedom to tailor the phase transition properties and may lead to energy-efficient and environmentally friendly gas liquefaction based on designed-for-purpose, noncritical multiferroic materials.. Authors: Beckmann, Benedikt [Technical Univ. of Darmstadt (Germany)] (ORCID:0000000222321804); Pfeuffer, Lukas [Technical Univ. of Darmstadt (Germany)]; Lill, Johanna [University of Duisburg-Essen (Germany)]; Eggert, Benedikt [University of Duisburg-Essen (Germany)] (ORCID:0000000177393541); Koch, David [Technical Univ. of Darmstadt (Germany)]. DOE Contract: AC02-06CH11357; FG02-94ER14466. Subjects: 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; Entropy; Gas liquefaction; La(Fe,Si)13-based compounds; Magnetic materials; Magnetic properties; Magnetocaloric; Materials; Multicaloric; Phase transitions; phase transitions