Scientists at the U.S. Department of Energy’s Ames Laboratory are attempting to improve the performance of a magnetic material that could be used in applications from space probes to power tools.

Bill McCallum, senior scientist at Ames Lab, and Alan Russell, associate scientist at the lab, are leading the project. They recently received a one-year, $165,000 research contract through the DOE and NASA.

The two are studying ways to improve neodymium-iron-boron magnets. Russell said they are trying to raise the Curie temperature of the material because the magnets currently lose their effectiveness just above room temperature.

“Every permanent magnet, if heated to a sufficiently high temperature, will lose its magnetism,” he said.

In the past, scientists tried to eliminate the heat problem by using different combinations of metals with non-varying composition. Russell said this approach is nearly exhausted.

“We may be about to play out this vein,” he said.

The new goal is to change the composition of the particle.

McCallum used an M&M candy as an analogy to explain the magnet technology. The candy is dark chocolate on the inside and gradually changes to milk chocolate on the outside. This type of material is called “functionally graded.”

“Each little piece of powder that makes up this large magnet will have one composition at its surface and [a different] one in the middle,” Russell said.

One problem the scientists must overcome is the extremely small scale of the particles with which they are working.

“We’re picturing something that’s anywhere from one to 10 microns across,” Russell said. By comparison, a human hair is about 60 microns wide.

Russell said improving this magnet could help NASA improve the efficiency of the reliable power sources they currently use for particular missions.

“They would like to get something that is 30 to 40 percent efficient to provide a lot more power with a lot less mass,” he said.

McCallum and Russell are working with a team of Ames Lab scientists and a technician on the project.

“The Ames Lab team working with us on this contract — Bruce Cook, Kevin Dennis, Joel Harringa, Fran Laabs, Tammie Bloomer and Les Reed — has a wealth of experience with rare-earth and magnetic materials,” Russell said. “They will be the keys to success for this project.”