Erbium-based magnetic refrigerant (regenerator) for passive cryocooler
AssigneeIowa State University Research Foundation, Inc.
InventorsKarl A. Gschneidner, Jr., Vitalij K. Pecharsky
Life of this patent
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Abstract
A two stage Gifford-McMahon cryocooler having a low temperature stage for reaching approximately 10K, wherein the low temperature stage includes a passive magnetic heat regenerator selected from the group consisting of Er.sub.6 Ni.sub.2 Sn, Er.sub.6 Ni.sub.2 Pb, Er.sub.6 Ni.sub.2 (Sn.sub.0.75 Ga.sub.0.25), and Er.sub.9 Ni.sub.3 Sn comprising a mixture of Er.sub.3 Ni and Er.sub.6 Ni.sub.2 Sn in the microstructure.
Claims11
A Gifford-McMahon cryocooler having a low temperature stage wherein the low temperature stage includes a passive magnetic regenerator selected from at least one material having atomic composition:
- about Er.sub.6 Ni.sub.2 Sn, about Er.sub.6 Ni.sub.2 Pb, and about Er.sub.6 Ni.sub.2 (Sn.sub.1-x Ga.sub.x) where x is greater than 0 and less than 1.
A Gifford-McMahon cryocooler having a low temperature stage wherein the low temperature stage includes a passive magnetic regenerator comprising Er.sub.9 Ni.sub.3 Sn alloy where there is present a mixture of Er.sub.3 Ni phase and Er.sub.6 Ni.sub.2 Sn phase in the microstructure of the alloy.
A passive magnetic regenerator selected from at least one material having atomic composition:
- about Er.sub.6 Ni.sub.2 Pb and about Er.sub.6 Ni.sub.2 (Sn.sub.1-x Ga.sub.x) where x is greater than 0 and less than 1, having a volumetric heat capacity greater than that of Er.sub.3 Ni between about 8K and about 19K and greater than that of Pb below about 18K.
A passive magnetic regenerator comprising a material having atomic composition Er.sub.9 Ni.sub.3 Sn and having a volumetric heat capacity greater than that of Er.sub.3 Ni between about 8K and about 19K and greater than that of Pb below about 18K.
An Er-based alloy selected from the group consisting of Er.sub.6 Ni.sub.2 Pb and Er.sub.6 Ni.sub.2 (Sn.sub.1-x Ga.sub.x) where x is greater than 0 and less than 1.
A cryocooler having a low temperature stage wherein the low temperature stage includes a passive magnetic regenerator selected from at least one material having atomic composition:
- about Er.sub.6 Ni.sub.2 Sn, about Er.sub.6 Ni.sub.2 Pb, and about Er.sub.6 Ni.sub.2 (Sn.sub.1-x Ga.sub.x) where x is greater than 0 and less than 1.
A cryocooler having a low temperature stage wherein the low temperature stage includes a passive magnetic regenerator comprising Er.sub.9 Ni.sub.3 Sn alloy where there is present a mixture of Er.sub.3 Ni phase and Er.sub.6 Ni.sub.2 Sn phase in the microstructure of the alloy.
A cryocooler having a low temperature stage wherein the low temperature stage includes a passive magnetic regenerator made from an alloy comprising about 66.7 atomic % Er, about 22.2 atomic % Ni, and about 11.1 atomic % of one of Sn, Pb, and Sn.sub.1-x Ga.sub.x, where x is greater than 0 and less than 1, said alloy having been heat treated and having a volumetric heat capacity greater than that of Er.sub.3 Ni between about 8K and about 19K and greater than that of Pb below about 18K.
A passive magnetic regenerator made from an as-cast or heat treated alloy comprising about 66.7 atomic % Er, about 22.2 atomic % Ni, and about 11.1 atomic % of one of Pb and Sn.sub.1-x Ga.sub.x, where x is greater than 0 and less than 1, said alloy having been heat treated and having a volumetric heat capacity greater than that of Er.sub.3 Ni between about 8K and about 19K and greater than that of Pb below about 18K.
Dependencies are inferred from the claim text.