Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

ORNL finding goes beyond surface of oxide films

14.08.2013
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 samples isolated from the atmosphere.

Researchers at the Department of Energy lab learned that key surface properties of complex oxide films are unaffected by reduced levels of oxygen during fabrication — an unanticipated finding with possible implications for the design of functional complex oxides used in a variety of consumer products, said Zheng Gai, a member of DOE’s Center for Nanoscale Materials Sciences at ORNL.


This figure shows the spectroscopic measurement (current as a function of voltage) and this as a function of temperature. (Reproduced by permission of The Royal Society of Chemistry)

The findings are detailed in a paper published in Nanoscale.

While the properties of the manganite material below the surface change as expected with the removal of oxygen, becoming an insulator rather than a metal, or conductor, researchers found that the sample showed remarkably stable electronic properties at the surface. Gai emphasized that the robustness of a surface matters because it is precisely the surface properties that determine, influence and affect the functionality of complex oxides in catalysis and batteries.

“With these materials being a promising alternative to silicon or graphene in electronic devices, the ever-decreasing size of such components makes their surface properties increasingly important to understand and control,” Gai said.

While this work provides a fundamental understanding of a material used and researched for catalysts, oxide electronics and batteries, Gai and lead author Paul Snijders noted that it’s difficult to speculate about possible impacts.

“I always say that in basic science we are discovering the alphabet,” said Snijders, a member of ORNL's Materials Science and Technology Division. “How these letters will be designed into a useful technological book is hard to predict.”

Making this discovery possible was the fact the authors did their experiment using scanning probe microscopy in a vacuum system with no exposure of the samples to the atmosphere. This contrasts with the conventional approach of growing a sample and then installing it in analysis equipment. During such a transfer, scientists expose the material to the water, nitrogen and carbon dioxide in the air.

By studying pristine samples, the ORNL team gained a surprising new understanding of the physics of the material surfaces — an understanding that is necessary to design new functional applications, Snijders said.

Other authors of the paper, titled “Persistent metal-insulator transition at the surface of an oxygen-deficient, epitaxial manganite film,” are Min Gao, Hangwen Guo, Guixin Cao, Wolter Siemons and Thomas Ward of ORNL, Hongjun Gao of the Chinese Academy of Sciences and Jian Shen of Fudan University, China. Min Gao and Snijders contributed equally to this work, which was funded by DOE’s Basic Energy Sciences. A portion of the research was conducted at the Center for Nanophase Materials Sciences. The paper is available at http://pubs.rsc.org/en/content/articlelanding/2013/nr/c3nr02343e.

CNMS is one of the five DOE Nanoscale Science Research Centers supported by the DOE Office of Science, premier national user facilities for interdisciplinary research at the nanoscale. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE's Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge, Sandia and Los Alamos national laboratories. For more information about the DOE NSRCs, please visit http://science.energy.gov/bes/suf/user-facilities/nanoscale-science-research-centers.

UT-Battelle manages ORNL for DOE's Office of Science. The Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit http://science.energy.gov/.

Ron Walli | EurekAlert!
Further information:
http://www.ornl.gov

More articles from Materials Sciences:

nachricht Argon is not the 'dope' for metallic hydrogen
24.03.2017 | Carnegie Institution for Science

nachricht Researchers make flexible glass for tiny medical devices
24.03.2017 | Brigham Young University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>