Technologies from wind turbines to electric vehicles rely on critical materials called rare-earth elements. These elements, though often abundant, can be difficult and increasingly costly to come by.

Now, scientists looking for alternatives have reported in ACS' journal Chemistry of Materials a new way to make nanoparticles that could replace some rare-earth materials and help ensure the continued supply of products people have come to depend on.

Rare-earth elements have unique characteristics that make them very useful. For example, the world's strongest magnets are made with neodymium. A little too powerful for your refrigerator, these magnets are incorporated into computer disk drives, power windows and wind turbines. But rare earths are challenging to mine and process, and prices can rise quickly in a short period of time.

Given the increasing demand for rare earths, Alberto Lopez-Ortega, Claudio Sangregorio and colleagues set out to find substitutes for use in strong magnets.

The researchers used a mixed iron-cobalt oleate complex in a one-step synthetic approach to produce magnetic core-shell nanoparticles. The resulting materials showed strong magnetic properties and energy-storing capabilities.

Their approach could signal an efficient new strategy toward replacing rare earths in permanent magnets and keeping costs stable, the researchers say.