The new iron-gallium alloy making a buzz in magnetoelectrics

12 May 2021571 Views

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Researchers claim their new material could slash the electricity requirements of the world’s computing infrastructure.

A group led by University of Michigan researchers has developed a new material for magnetoelectric devices. The team claims that the material is twice as magnetostrictive, more energy efficient and less costly than others in its category.

Magnetoelectric devices store data with magnetic fields instead of electricity. One of their primary properties is magnetostriction, which occurs when a material’s shape and magnetic field are linked. If the material’s shape changes, so does its magnetic field. Magnetostriction is what causes fluorescent lamps and electrical transformers to hum.

The researchers said that using this property to develop magnetoelectric chips could slash the electricity requirements of the world’s computing infrastructure and improve the energy efficiency of everything from data centres to smartphones. This is because they don’t require a steady stream of electricity like other chips.

“A key to making magnetoelectric devices work is finding materials whose electrical and magnetic properties are linked,” said Prof John Heron, the research lead.

“And more magnetostriction means that a chip can do the same job with less energy.”

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Heron and his team’s new material combines iron and gallium. These offer a less expensive and more abundant alternative to the rare-earth elements typically required for magnetostrictive materials.

To create their magnetostrictive iron-gallium material, the researchers used a process call low-temperature molecular-beam epitaxy. This technique meant they could add more gallium to the material and, ultimately, achieve a tenfold increase in magnetostriction compared with other iron-gallium alloys that hadn’t been modified in this way.

“It’s a little bit like spray painting with individual atoms,” Heron explained. “And ‘spray painting’ the material onto a surface that deforms slightly when a voltage is applied also made it easy to test its magnetostrictive properties.”

The team’s magnetoelectric devices are large by current computing standards, measuring several microns. But researchers are working with Intel on shrinking them down to more usable sizes.

Their paper, published in Nature Communications, said that a device using this material is likely still decades away. However, the team has filed for patent protection and said that in addition to a potential for computing, the magnetoelectric chips could also lead to better magnetic sensors for medical and security devices.

Lisa Ardill was careers editor at Silicon Republic until June 2021

editorial@siliconrepublic.com