Scientists create cheaper magnetic material for cars, wind turbines

April 24, 2015 by Laura Millsaps, Ames Laboratory
Scientist Arjun Pathak arc melts material in preparation for producing a new type of magnet.

Karl A. Gschneidner and fellow scientists at the U.S. Department of Energy's Ames Laboratory have created a new magnetic alloy that is an alternative to traditional rare-earth permanent magnets.

The new alloy—a potential replacement for high-performance permanent magnets found in automobile engines and wind turbines—eliminates the use of one of the scarcest and costliest , , and instead uses cerium, the most abundant rare earth.

The result, an alloy of neodymium, iron and boron co-doped with cerium and cobalt, is a less expensive material with properties that are competitive with traditional sintered magnets containing dysprosium.

Experiments performed at Ames Laboratory by post-doctoral researcher Arjun Pathak, and Mahmud Khan (now at Miami University) demonstrated that the cerium-containing alloy's intrinsic coercivity—the ability of a magnetic material to resist demagnetization—far exceeds that of dysprosium-containing magnets at high temperatures. The materials are at least 20 to 40 percent cheaper than the dysprosium-containing magnets.

"This is quite exciting result; we found that this material works better than anything out there at temperatures above 150° C," said Gschneidner. "It's an important consideration for high-temperature applications."

Previous attempts to use cerium in rare-earth magnets failed because it reduces the Curie temperature—the temperature above which an alloy loses its properties. But the research team discovered that co-doping with cobalt allowed them to substitute for dysprosium without losing desired magnetic properties.

Finding a comparable substitute material is key to reducing manufacturing reliance on dysprosium; the current demand for it far outpaces mining and recycling sources for it.

The paper, "Cerium: An Unlikely Replacement of Dysprosium in High Performance Nd-Fe-B Permanent Magnets" was published in Advanced Materials.

Explore further: Toshiba develops dysprosium-free samarium-cobalt magnet to replace heat-resistant neodymium magnet

More information: "Cerium: An Unlikely Replacement of Dysprosium in High Performance Nd–Fe–B Permanent Magnets." Adv. Mater., 27: 2663–2667. DOI: 10.1002/adma.201404892

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Whydening Gyre
5 / 5 (5) Apr 24, 2015
I find it rather refreshing that there appears almost as many ways to combine different things as there are things to combine, here in our Universe...:-)
"I love this bar...:-)"
3.6 / 5 (5) Apr 24, 2015
So much for the "resource problem" with alternative energy systems.
Da Schneib
5 / 5 (3) Apr 24, 2015
Good stuff. This will work in all sorts of things that require permanent magnets, for example this:
not rated yet May 20, 2015
So much for the "resource problem" with alternative energy systems.

There's still neodymium, which is not as rare but nevertheless a strategic resource controlled mainly by China, who is imposing export controls to pump up prices.

For example: one electric car requires about 1 kg of neodymium in its motors. The current world production would be enough for about 7-10 million new electric vehicles per year.

There are about 16 million new cars sold in the US alone every year. Should the electric car market explode in the near future, there won't be any neodymium left over for the rest.
not rated yet May 20, 2015
@Eikka: Never heard about recycling?

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