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Tunable Magnetic Regenerator/Refrigerant

Ames Laboratory

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Technology Marketing Summary

Magnetic regenerators utilize the magnetocaloric effect--the ability of a magnetic field to reduce the magnetic part of a solid materials entropy, generating heat, and then removing the magnetic field, permitting the reduction of temperature with the change in entropy. The cyclic heat generation and absorption in adiabatic magnetization and demagnetization. This invention uses a specific mix of rare earth magnetic materials capable of producing both a first and second order phase transitions upon heating and cooling, with the application and the removal of a magnetic field. The transitions aids in the temperature range that can be used for cooling and/or heating.

Description

This discovery has a number of new potential applications which were before thought to be outside the realm of possibilities for magnetic refrigeration. These include automotive and home air conditioning (HVAC) using permanent magnets instead of superconducting magnets, and use in electrical vehicle climate control systems. Also, these new materials will greatly improve the efficiency of magnetic refrigeration technology and facilitate the use of active magnetic refrigeration in food processing plant refrigerators and freezers; supermarket chillers; large scale building air conditioners; production of chemicals which require cooling, such as chlorine, ammonia, ethylene and polyethylene; and liquefaction of gases such as propane, natural gas (methane) and hydrogen. This series of alloys will be the workhorse material for magnetic refrigeration for many years into the future because of the giant magnetocaloric effect and its tunability. They will be the prototype materials, and their properties will be difficult to match, let alone exceed.

Benefits
  • Aids in the temperature range that can be used for cooling and/or heating
  • Will greatly improve the efficiency of magnetic refrigeration technology
Applications and Industries

Applications exist anywhere there is need for freezing, heating, or cooling. Industries which produce cryogenics systems; supermagnets; and HVAC systems for homes, vehicular transports and other applications will be interested in this technology.

Patents and Patent Applications
ID Number
Title and Abstract
Primary Lab
Date
Patent 5,743,095
Patent
5,743,095
Active magnetic refrigerants based on Gd-Si-Ge material and refrigeration apparatus and process
Active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or less than 0.5, as a magnetic refrigerant that exhibits a reversible ferromagnetic/antiferromagnetic or ferromagnetic-II/ferromagnetic-I first order phase transition and extraordinary magneto-thermal properties, such as a giant magnetocaloric effect, that renders the refrigerant more efficient and useful than existing magnetic refrigerants for commercialization of magnetic regenerators. The reversible first order phase transition is tunable from approximately 30 K to approximately 290 K (near room temperature) and above by compositional adjustments. The active magnetic regenerator and method can function for refrigerating, air conditioning, and liquefying low temperature cryogens with significantly improved efficiency and operating temperature range from approximately 10 K to 300 K and above. Also an active magnetic regenerator and method using Gd.sub.5 (Si.sub.x Ge.sub.1-x).sub.4, where x is equal to or greater than 0.5, as a magnetic heater/refrigerant that exhibits a reversible ferromagnetic/paramagnetic second order phase transition with large magneto-thermal properties, such as a large magnetocaloric effect that permits the commercialization of a magnetic heat pump and/or refrigerant. This second order phase transition is tunable from approximately 280 K (near room temperature) to approximately 350 K by composition adjustments. The active magnetic regenerator and method can function for low level heating for climate control for buildings, homes and automobile, and chemical processing.
Ames Laboratory 04/28/1998
Issued
Technology Status
Technology IDDevelopment StageAvailabilityPublishedLast Updated
02064DevelopmentAvailable12/07/201212/07/2012

Contact AMES About This Technology

To: Stacy Joiner<joiner@ameslab.gov>