Unexpected phenomenon discovered at the surface of a transition metal oxide material

Aug 01, 2014
J.D. Burton, left, and Evgeny Tsymbal. Credit: Troy Fedderson/University Communications

(Phys.org) —An international team of scientists, including University of Nebraska-Lincoln physicists J. D. Burton and Evgeny Tsymbal, has discovered what they called an intriguing and entirely unexpected phenomenon at the surface of a transition metal oxide material. Such materials serve as a hotbed for electrochemical applications like solid fuel cells and oxygen sensors, as well as potential applications in future electronic devices.

"Our work shows that it's possible to detect and characterize the smallest features on the surfaces of , even down to the atomic scale," said Burton, a research assistant professor of physics. "This could lead to huge advancements in the understanding and control of electronic, magnetic and chemical properties of this important class of materials."

The findings were reported in the July 24 issue of Nature Communications, the Nature Publishing Group's multidisciplinary online journal of research in all areas of the biological, physical and chemical sciences.

The discovery is based on scanning tunneling microscopy, or STM, of samples prepared and measured at Oak Ridge National Laboratory in Tennessee. Using atomic scale STM measurements, researchers were able to map out the precise positions of oxygen atoms on the surface of this oxide. Surprisingly, it was found that oxygen atoms not only order in a regular array of sites, but superimposed on this regular array was a subtle zig-zag like pattern of distortions.

The nature of this zig-zag-like phenomenon was first unclear to the scientists, but Burton and Tsymbal were able to discover the explanation by modeling the atomic structure and electronic properties of the material surface through computations at UNL's Holland Computing Center. Results indicated that changes in the electronic structure of the surface due to the presence of extra led to a subtle structural transformation of the material just below the surface.

"Crucially, our computations and analysis were decisive for the understanding of the origin of this phenomenon," Burton said. "We were able to elucidate the microscopic mechanism responsible for this exciting discovery."

Collaborative research on complex oxide materials is one of the constituents of UNL's Materials Research Science and Engineering Center supported by the National Science Foundation.

"This remarkable finding shows the deep underlying physics controlling properties of these materials," said Tsymbal, George Holmes Professor of Physics and director of the center. "It also demonstrates the critical importance of collaborations between experimentalists and theorists in elucidating new phenomena."

It's the seventh time in last four years that research from Tsymbal's group has been published in of the highest-impact interdisciplinary journals such as Science, the Proceedings of the National Academy of Sciences, and Nature Publishing Group.

Explore further: Study reveals new characteristics of complex oxide surfaces

add to favorites email to friend print save as pdf

Related Stories

The quest to discover new technology

Feb 21, 2011

Electronic devices like smart phones, computers and mp3 players have become central pieces of everyday life and consumers have grown accustomed to seeing new and improved models every time they turn around. But continuing ...

ORNL finding goes beyond surface of oxide films

Aug 13, 2013

(Phys.org) —Better batteries, catalysts, electronic information storage and processing devices are among potential benefits of an unexpected discovery made by Oak Ridge National Laboratory scientists using ...

'Exotic' material is like a switch when super thin

Apr 18, 2014

(Phys.org) —Ever-shrinking electronic devices could get down to atomic dimensions with the help of transition metal oxides, a class of materials that seems to have it all: superconductivity, magnetoresistance ...

Recommended for you

WEGA fusion experiment passed on to the USA

15 hours ago

The small WEGA fusion device at Max Planck Institute of Plasma Physics (IPP) in Greifswald is being handed over to the University of Illinois in Urbana-Champaign. The "Wendelstein-Experiment in Greifswald ...

Researchers design plasmonic cavity-free nanolaser

16 hours ago

(Phys.org) —A team of researchers at Imperial College in London has designed a new type of laser, one that could be made much smaller than today's models because it would be cavity-free. In their paper ...

Uncovering the forbidden side of molecules

Sep 21, 2014

Researchers at the University of Basel in Switzerland have succeeded in observing the "forbidden" infrared spectrum of a charged molecule for the first time. These extremely weak spectra offer perspectives ...

User comments : 0