Magnetostriction is a property of magnetic materials that causes fluorescent lights and electrical transformers to buzz. This property causes the materials to change shape or dimensions as the magnetic field changes.
Magnetostriction also plays a big part in a new material that could lead to more energy-efficient computing. The research team that developed the material is led by the University of Michigan, and researchers from the University of Wisconsin and Purdue University also are participating.
The new material is twice as magnetostrictive and much cheaper than similar materials. It could contribute to magnetostrictive chips, which would cut the energy consumption of a wide range of electronics from cell phones to huge data centers.
Making the material
Magnetoelectric devices store data by using magnetic fields. Tiny pulses of electricity cause them to change the magnetic field back and forth between positive and negative charges. They don’t require a constant stream of electricity like current computer chips, so they use a fraction of the energy.
“A key to making magnetoelectric devices work is finding materials whose electrical and magnetic properties are linked.” University of Michigan materials science and engineering professor John Heron said in a news release.
“And more magnetostriction means that a chip can do the same job with less energy.”
The team made devices that are just several microns in size, but that’s large by computing standards. The researchers are working with Intel to figure out how to get the magnetoelectric chips to a smaller, more useful size.
Reworking the rare components
Most magnetoelectric materials typically are made from rare-earth elements. These elements can be environmentally taxing to mine. They are also expensive, making it impractical to use current magnetoelectric materials for computing devices on a widespread scale.
The new material is made from the elements iron and gallium. The research team used a process that essentially freezes the atoms in place to alter the amount of gallium in the structure. They doubled the amount of gallium, which increased the magnetostriction tenfold.
“[This process] is an extremely useful technique — it’s a little bit like spray painting with individual atoms,” Heron said. “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 research lab has filed for patent protection for this new magnetostrictive material. They acknowledge it will likely be decades before a device that uses this material becomes mainstream.