Lawrence Berkeley National Laboratory scientists have developed a new “magnetoelectric multiferroic*” material that could lead to a new generation of computing devices with more computing power while consuming a fraction of the energy that today’s electronics require.
“Electronics are the fastest-growing consumer of energy worldwide,” said Ramamoorthy Ramesh, associate laboratory director for energy technologies at Lawrence Berkeley National Laboratory.
“Today, about five percent of our total global energy consumption is spent on electronics, and that’s projected to grow to 40–50 percent by 2030 if we continue at the current pace and if there are no major advances in the field that lead to lower energy consumption.”
Global or world energy consumption is the total energy used by all of human civilization. The U.S. Energy Information Administration estimates that in 2013, world energy consumption was 157,481 terawatt hours (TWh), mainly from polluting expendables — oil, coal, and natural gas.
The new material, which combines electrical and magnetic properties at room temperature, could help reduce this consumption in the future.
The newly developed material sandwiches together individual layers of atoms, producing a thin film with magnetic polarity that can be “flipped” from positive to negative or vice versa with small pulses of electricity.
In the future, device makers could use this property to store digital 0’s and 1’s, the binary backbone that underpins computing devices.
“Before this work, there was only one other room-temperature multiferroic whose magnetic properties could be controlled by electricity,” said John Heron, assistant professor in the Department of Materials Science and Engineering at the University of Michigan, who worked on the material with researchers at Cornell University. “That electrical control is what excites electronics makers, so this is a huge step forward.”
Room-temperature multiferroics are a hotly pursued goal in the electronics field because they require 100 times less power to read and write data than today’s semiconductor-based devices. In addition, they are nonvolatile (their data doesn’t vanish when the power is shut off).
Those properties could enable devices that require only brief pulses of electricity instead of the constant stream that’s needed for current electronics, resulting in using an estimated 100 times less energy.
To create the new material, the researchers started with thin, atomically precise films of hexagonal lutetium iron oxide (LuFeO3), a material known to be a robust ferroelectric, but not strongly magnetic. Lutetium iron oxide consists of alternating monolayers of lutetium oxide and iron oxide. They then used a technique called molecular-beam epitaxy (which takes place in a high vacuum) to add one extra monolayer of iron oxide to every 10 atomic repeats of the single-single monolayer pattern.
“We were essentially spray painting individual atoms of iron, lutetium and oxygen to achieve a new atomic structure that exhibits stronger magnetic properties,” said Darrell Schlom, a materials science and engineering professor at Cornell and senior author of a paper on the work recently published in Nature.
The result was a new material that combines a phenomenon in lutetium oxide called “planar rumpling” with the magnetic properties of iron oxide to achieve multiferroic properties at room temperature.