Materials - Ferroelectric fury
By discovering a technique to guide the ferroelectric switching process in bismuth ferrite, a team led by Oak Ridge National Laboratory's Nina Balke has moved one step closer to developing more rugged memory and logic devices. One key to the success is that the material has both electrical and magnetic properties at the same time, which is unusual. By controlling the polarization switching it is possible to alter magnetization states as well due to parameter coupling, which can be used to store information. Using a one-of-a-kind scanning probe in research funded by ORNL's Laboratory Directed Research and Development program, Balke was able to select among final polarization states that have the same electrostatic energy but differ dramatically in elastic or magnetic order. Remarkably, the control of polarization switching allowed the authors to create the closure ferroelectric domain pattern, the precursor for the long-theorized ferroelectric vortex state. Funding for this work, published in Nature Nanotechnology, was provided by the Department of Energy's Office of Basic Energy Sciences and the National Science Foundation. The work was performed at ORNL's Center for Nanophase Materials Science.
November 05, 2009