Revolutionizing refrigerators.

• Position: Magnetics - Brief Article

Using materials developed at the U.S. Department of Energy's Ames (Iowa) Laboratory, researchers have successfully demonstrated the world's first room-temperature, permanent-magnet, magnetic refrigerator. Instead of ozone-depleting refrigerants and energy-consuming compressors found in conventional vapor-cycle refrigerators, it uses gadolinium metal that heats up when exposed to a magnetic field, then cools down when the magnetic field is removed.

According to Karl Gschneidner Jr., Anson Marston Distinguished Professor of Materials Science and Engineering at Iowa State University, the magnetic refrigerator employs a rotary design. It consists of a wheel that contains segments of gadolinium powder and a high-powered, rare earth permanent magnet. The wheel is arranged so it can pass through a gap in the magnet where the magnetic field is concentrated. As it passes through this field, the gadolinium exhibits a large magnetocaloric effect--it heats up...