by Catherine Foster

Permanent magnets are important in a broad variety of commercial technologies, from car starters to alternators for wind power generation to computer hard drives. Researchers at the Department of Energy's Argonne National Laboratory (ANL) have found new clues to making those magnets longer-lasting and more powerful.

Using the Western Hemisphere's most powerful X-rays at ANL’s Advanced Photon Source, the researchers were able to see new details of rare-earth ions, a critical component of permanent magnets. Examination of the ions, probing their magnetism with unprecedented resolution, revealed that the presence of rare-earth ions in more than one atomic environment reduces the magnetic stability of the best-performing permanent magnets to date. This knowledge will enable manufacturers to manipulate the rare-earth ion atomic structure to optimize future magnets.

The research was published in November in Physical Review Letters.

Rare-earth ions come from metallic elements that share similar chemical properties; they are not especially rare, but they are used sparingly because of the high cost to prepare the materials. Rare-earth ions play an important role in determining magnetic stability against demagnetizing fields and therefore in magnet performance.

“The research found that rare-earth ions in dissimilar crystalline environments compete with one another and undermine the magnetic performance of the highest performance magnets,” said ANL scientist Daniel Haskel, who led the research team. “These findings point to the need for specialized atomic engineering of the material—manipulating the rare-earth local atomic structure to fully utilize the rare-earth contribution in next generations of magnets.”

Other authors of the paper are Jonathan C. Lang, Zahirul Islam, Andrew Cady and George Srajer, all of the Experimental Facilities Division of the Advanced Photon Source; Michel van Veenendaal of Northern Illinois University; and Paul C. Canfield of Iowa State University.

The nation's first national laboratory, Argonne National Laboratory conducts basic and applied scientific research across a wide spectrum of disciplines ranging from high-energy physics to climatology and biotechnology. Since 1990, ANL has worked with more than 600 companies and numerous federal agencies and other organizations to advance America's scientific leadership and prepare the nation for the future. ANL is managed by the University of Chicago for the Department of Energy's Office of Science.

For more information:

Contact Catherine Foster, 630-252-5580 or cfoster@anl.gov.