Metallic local-moment magnetocalorics as a route to cryogenic refrigeration

Abstract

Commercial adiabatic demagnetisation refrigerators still employ the same hydrated salts that were first introduced over 85 years ago. The inherent limitations of these insulating magnetocalorics - poor thermal conductivity at sub-Kelvin temperatures, low entropy density, corrosiveness - can be overcome by a new generation of rare-earth based metallic magnetocalorics. Here, we present the metallic magnetocaloric YbNi1.6 Sn as an attractive alternative to conventional refrigerants. YbNi1.6Sn retains high entropy into the 100 mK regime and avoids the noble metal constituents of alternative refrigerants. Demagnetisation tests demonstrate that YbNi1.6Sn enables economical and durable alternatives to traditional cooling devices for temperatures reaching below 120 mK. We find that the magnetocaloric properties of this material are facilitated by unusually small Kondo and RKKY interactions, which position YbNi1.6Sn in the extreme local moment limit on the generalised Kondo lattice phase diagram.

arXiv comment9 pages, 4 figures

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• Quantum Computing
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• Frustrated magnet for adiabatic demagnetization cooling to milli-Kelvin temperatures
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• Magnetic field induced non-Fermi liquid to Fermi liquid crossover at the quantum critical point of YbCu${}_{5-x}$Au${}_x$
• Local moment physics in heavy electron systems
• Physical properties of the very heavy fermion YbCu4Ni
• Thermal and magnetic properties of a low-temperature antiferromagnet Ce${}_4$Pt${}_{12}$Sn${}_{25}$

Cited by in corpus (2)

• Utilizing frustration in Gd- and Yb-based oxides for milli-Kelvin adiabatic demagnetization refrigeration
• Giant Magnetocaloric Effect in a Honeycomb Spiral Spin-Liquid Candidate