Breakthrough research could increase memory storage capacity
1 min read
Researchers at the University of Michigan have found a way to improve the performance of ferroelectric materials, which they claim has the potential to make memory devices with more storage capacity than magnetic hard drives, as well as faster write speed and longer lifetimes than flash memory.
In collaboration with Cornell University, Penn State University and the University of Wisconsin, Professor Xiaoqing Pan designed a material system that spontaneously forms small nano sized spirals of the electric polarisation at controllable intervals. Prof Pan believes it could provide natural budding sites for the polarisation switching and thus reduce the power needed to flip each bit.
"To change the state of a ferroelectric memory, you have to supply enough electric field to induce a small region to switch the polarisation," said Prof Pan. "With our material, such a nucleation process is not necessary. The nucleation sites are intrinsically there at the material interfaces."
To achieve this, the engineers layered a ferroelectric material on an insulator with closely matched crystal lattices. The polarisation caused large electric fields at the ferroelectric surface that were responsible for the spontaneous formation of the budding sites, known as 'vortex nano domains'.
The researchers also mapped the material's polarisation with atomic resolution and used images from a sub angstrom resolution transmission electron microscope at Lawrence Berkeley National Laboratory. They also developed image processing software to accomplish this.
"This type of mapping has never been done before," said Pan. "Using this technique, we've discovered unusual vortex nano domains in which the electric polarisation gradually rotates around the vortices."
This research was funded by the Department of Energy, the National Science Foundation and the US Army Research Office.
