Researchers at the University of Wisconsin-Madison have designed a device capable of combining two different ways of storing information. This low-power, multifunctional technology is called a ‘magnetoelectric’ device, and it could permanently change how we store data.
Magnetoelectric materials are a rare breed. They possess both magnetic and electrical functionalities. Switching the functionality of one causes a change in the other. This is known as ‘cross-coupling.’ While scientists understand this in theory, how cross-coupling works has long been a mystery.
Scientists dealt with this conundrum by studying how magnetic properties changed when they applied an electric field into the mix. This has only recently become an option for researchers, as most magnetoelectric materials are incredibly complex. To achieve this goal, scientists had to create a simpler magnetoelectric material.
Using atomic steps, scientists were able to construct a simple magnetoelectric material. This involved guiding the growth of a homogonous, super-thin film of bismuth ferrite. Cobalt was added to the top for its magnetic properties. At the bottom of the material an electrode made of strontium ruthenate was attached. This unusual combination led to a simple material that made studying cross-coupling easier than ever before.
“We found that in our work, because of our single domain, we could actually see what was going on using multiple probing, or imaging, techniques. The mechanism is intrinsic. It’s reproducible — and that means you can make a device without any degradation, in a predictable way.”
Powerful synchroton light sources were used to image the changing electric and magnetic properties as they switched in real time. The light sources used came from locations as diverse as Argonne National Laboratory near Chicago, the United Kingdom, and Switzerland.
When switched, the electrical field switches its electric polarization. This causes the coupling to the magnetic layer to change properties. And there you have it: a magnetoelectric storage device. The directional change is a major factor in this technology; it will allow researchers to add a variety of integrated, programmable circuits.
While the material has numerous applications within laboratory settings, its impact goes far beyond a lab. Researchers believe that this technology could be used to improve consumer electronics, providing us with magnetoelectric data storage devices that are low-power and extremely efficient.
