Large magnetocaloric effect and adiabatic demagnetization refrigeration with YbPt2Sn.
Adiabatic demagnetization is currently gaining strong interest in searching for alternatives to (3)He-based refrigeration techniques for achieving temperatures below 2 K. The main reasons for that are the recent shortage and high price of the rare helium isotope (3)He. Here we report the discovery of a large magnetocaloric effect in the intermetallic compound YbPt2Sn, which allows adiabatic demagnetization cooling from 2 K down to 0.2 K. We demonstrate this with a home-made refrigerator. Other materials, for example, paramagnetic salts, are commonly used for the same purpose but none of them is metallic, a severe limitation for low-temperature applications. YbPt2Sn is a good metal with an extremely rare weak magnetic coupling between the Yb atoms, which prevents them from ordering above 0.25 K, leaving enough entropy free for use in adiabatic demagnetization cooling. The large volumetric entropy capacity of YbPt2Sn guarantees also a good cooling power.
Max Planck Institute for Chemical Physics of Solids, Noethnitzer Strasse 40, D-01187 Dresden, Germany.
Dongjin
D
Jang
Max Planck Institute for Chemical Physics of Solids, Noethnitzer Strasse 40, D-01187 Dresden, Germany.
Thomas
T
Gruner
Max Planck Institute for Chemical Physics of Solids, Noethnitzer Strasse 40, D-01187 Dresden, Germany.
Alexander
A
Steppke
Graduate School of Science and Technology, Niigata University, 8050, Ikarashi 2-nocho, Niigata 950-2181, Japan.
Keisuke
K
Mitsumoto
Max Planck Institute for Chemical Physics of Solids, Noethnitzer Strasse 40, D-01187 Dresden, Germany.
Christoph
C
Geibel
Max Planck Institute for Chemical Physics of Solids, Noethnitzer Strasse 40, D-01187 Dresden, Germany.
Manuel
M
Brando