U.S. Department of Energy’s Brookhaven National Laboratory researchers have noticed that joining magnetic and electric properties can coexist in a special class of metals. Those materials “multiferroics” could be used as basis for next generation of memory, and sensing technology that are faster and more energy efficient.
The researchers, who worked with colleagues at the Leibniz Institute for Solid State and Materials Research in Germany, published their findings online in Physical Review Letters on July 25, 2011.
Ferromagnets are materials that display a permanent magnetic moment, or magnetic direction, similar to how a compass needle always points north. They assist in a variety of daily tasks, from sticking a reminder to the fridge door to storing information on a computer’s hard drive. Ferroelectrics are materials that display a permanent electric polarization — a set direction of charge — and respond to the application of an electric field by switching this direction. They are commonly used in applications like sonar, medical imaging, and sensors.
Now, scientists have found a new way that electric and magnetic properties can be coupled in a material. The group used extremely bright beams of x-rays at Brookhaven’s National Synchrotron Light Source (NSLS) to examine the electronic structure of a particular metal oxide made of yttrium, manganese, and oxygen. They determined that the magnetic-electric coupling is caused by the outer cloud of electrons surrounding the atom.