Magnetic refrigeration is a cooling technology presently (
2003) being developed by a partnership of the
United States Department of Energy's Ames Laboratory and Astronautics Corp. of America. A proof-of-principle model was successfully demonstrated in
1996.
The technology uses the magnetocaloric effect[?], which is the tendency of certain materials, such as the metallic element gadolinium, to heat up when placed in a magnetic field and to cool down when removed from the field.
Ames Laboratory news release of May 25, 1999 at
http://www.ameslab.gov/News/release/crada.html.