Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

ORNL scientists crack materials mystery in vanadium dioxide

24.11.2010
A systematic study of phase changes in vanadium dioxide has solved a mystery that has puzzled scientists for decades, according to researchers at the Department of Energy's Oak Ridge National Laboratory.

Scientists have known that vanadium dioxide exhibits several competing phases when it acts as an insulator at lower temperatures. However, the exact nature of the phase behavior has not been understood since research began on vanadium dioxide in the early 1960s.

Alexander Tselev, a research associate from the University of Tennessee-Knoxville working with ORNL's Center for Nanophase Materials Sciences, in collaboration with Igor Luk'yanchuk from the University of Picardy in France used a condensed matter physics theory to explain the observed phase behaviors of vanadium dioxide, a material of significant technological interest for optics and electronics.

"We discovered that the competition between several phases is purely driven by the lattice symmetry," Tselev said. "We figured out that the metallic phase lattice of vanadium oxide can 'fold' in different ways while cooling, so what people observed was different types of its folding."

Vanadium dioxide is best known in the materials world for its speedy and abrupt phase transition that essentially transforms the material from a metal to an insulator. The phase change takes place at about 68 degrees Celsius.

"These features of electrical conductivity make vanadium dioxide an excellent candidate for numerous applications in optical, electronic and optoelectronic devices," Tselev said.

Devices that might take advantage of the unusual properties of VO2 include lasers, motion detectors and pressure detectors, which could benefit from the increased sensitivity provided by the property changes of vanadium dioxide. The material is already used in technologies such as infrared sensors.

Researchers said their theoretical work could help guide future experimental research in vanadium dioxide and ultimately aid the development of new technologies based on VO2.

"In physics, you always want to understand how the material ticks," said Sergei Kalinin, a senior scientist at the CNMS. "The thermodynamic theory will allow you to predict how the material will behave in different external conditions."

The results were published in the American Chemical Society's Nano Letters. The research team also included Ilia Ivanov, John Budai and Jonathan Tischler at ORNL and Evgheni Strelcov and Andrei Kolmakov at Southern Illinois University.

The team's theoretical research expands upon previous experimental ORNL studies with microwave imaging that demonstrated how strain and changes of crystal lattice symmetry can produce thin conductive wires in nanoscale vanadium dioxide samples.

This research was supported in part by the Department of Energy's Office of Science and by the National Science Foundation. Researchers also used instrumentation at the Office of Science-supported Center for Nanophase Materials Sciences and Advanced Photon Source User Facilities at Oak Ridge and Argonne national laboratories, respectively.

CNMS is one of the five DOE Nanoscale Science Research Centers, premier national user facilities for interdisciplinary research at the nanoscale supported by the DOE Office of Science. 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 and Sandia and Los Alamos National Laboratories. For more information about the DOE NSRCs, please visit http://nano.energy.gov.

ORNL is managed by UT-Battelle for the Department of Energy's Office of Science.

NOTE TO EDITORS: You may read other press releases from Oak Ridge National Laboratory or learn more about the lab at http://www.ornl.gov/news. Additional information about ORNL is available at the sites below:

Twitter - http://twitter.com/oakridgelabnews

RSS Feeds - http://www.ornl.gov/ornlhome/rss_feeds.shtml

Flickr - http://www.flickr.com/photos/oakridgelab

YouTube - http://www.youtube.com/user/OakRidgeNationalLab

LinkedIn - http://www.linkedin.com/companies/oak-ridge-national-laboratory

Facebook - http://www.facebook.com/Oak.Ridge.National.Laboratory

Morgan McCorkle | EurekAlert!
Further information:
http://www.ornl.gov

Further reports about: Laboratory Materials Science NSRCs Nanophase ORNL Science TV VO2 vanadium dioxide

More articles from Materials Sciences:

nachricht Reliable molecular toggle switch developed
30.03.2017 | Karlsruher Institut für Technologie (KIT)

nachricht Researchers shoot for success with simulations of laser pulse-material interactions
29.03.2017 | DOE/Oak Ridge National Laboratory

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

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...

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

'On-off switch' brings researchers a step closer to potential HIV vaccine

30.03.2017 | Health and Medicine

Penn studies find promise for innovations in liquid biopsies

30.03.2017 | Health and Medicine

An LED-based device for imaging radiation induced skin damage

30.03.2017 | Medical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>