Magnetic Refrigeration Material with Extraordinary Magnetocaloric Properties Above and Near Room Temperature
Project Leaders: Naushad Ali, Shane Stadler, Mahmud Khan
Unit: Department of Physics
Executive Summary:
The invention is a material that exhibits a performance for giant magnetocaloric effect (GMCE) above and near room temperature that is twice that of the best performance ever previously observed in a magnetic refrigerant material. Magnetic refrigeration can be used to achieve extremely low temperatures as well as the ranges commonly used in refrigerators, heat pumps, freezers, and air conditioners, with higher efficiency and a small environmental impact that existing technologies. [News Article from SIUC Perspectives Spring 2007 Issue, most recent DOE grant information]
Patent Status:
Patent pending. U.S. Patent application number 20080276623 , published November 13, 2008.
Potential Commercial Uses:
The global commercial refrigeration equipment industry size was $23.4 billion in 2007 with projected growth of 4.6 percent annually through 2012, exceeding $9 billion in the US (source). Gains are coming from the growing number of foodservice operators and food retailers and consumers' increasing demand for a wide variety of refrigerated foods.
Benefits and Competitive Advantages:
- Environmentally friendly technology: Higher energy efficiency than compressed-gas systems, with no harmful gases (CFC, NH3, HFC)
- Simple mechanisms with few moving parts
- While outperforming other materials in GMCE, the invention also displays other properties necessary as a magnetic refrigerant material: significant MCE at reasonable magnetic field values, reversible magnetostructural transition, minimal hysteresis losses, transition in usable temperature range, and composed of environmentally friendly, affordable and non-toxic materials
Brief Description:
This invention generally relates to magnetic refrigerant materials, and more particularly, to magnetic refrigerant materials that exhibit a sufficiently great magnetocaloric effect near or at room temperature, and also relates to a regenerator and a magnetic refrigerator that use these magnetic refrigerant materials. Specific embodiments of magnetocaloric materials useful in magnetic refrigeration systems, for example, are disclosed. The magnetocaloric materials include nickel-manganese-gallium (NiMnGa) alloys in which substitution is made from some of the manganese. Copper is preferably substituted for at least some of the manganese, but cobalt or a combination of cobalt and copper could also be substituted for at least some of the manganese. In the preferred embodiment, the material comprises a nickel-manganese-copper-gallium of the composition Ni.sub.2Mn.sub.1-xCu.sub.xGa, where x is greater than or equal to about 0.22.
Keywords:
Naushad Ali, Mahmud Khan, Shane Stadler, magnetic refrigeration, magnetic refrigerant material, magnetocaloric effect, magnetic cooling, commercial cooling devices, refrigeration technology, room temperature magnetocaloric effect, SIUC Department of Physics, SIUC Materials Technology Center
Contact:
Jeff Myers, Senior Technology Transfer Specialist, (618) 453-4543, fax: (618) 453-8038