A matter of performance and criticality: A review of rare-earth-based magnetocaloric intermetallic compounds for hydrogen liquefaction

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

“…Even though magnetocaloric cooling has been predominantly tailored for room temperature applications, one of its first utilizations realized ultralow temperatures below 1 K by adiabatic demagnetization of paramagnetic salts. , Very recent results on Laves phases and HoB 2 are a manifestation of currently re-emerging interest in caloric cooling at cryogenic temperatures, at the present time in the framework of gas liquefaction, which allows the utilization of superconducting magnets and thereby large external magnetic fields driving the phase transitions. − However, the reliance of current magnetocaloric materials on highly resource critical, − heavy rare-earth elements, such as Er, Dy, and Ho, though important for fundamental research and device development, makes global commercial usage unsustainable . In addition, monocaloric cooling requires the stacking of numerous different chemical compositions in order to provide sufficient cooling power over a large enough temperature range, and these chemical modifications often destabilize the desired magnetocaloric active phase, leading to impurities, reduced caloric effects, and an overall more complex material synthesis process.…”