Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > ORNL microscopy inspires flexoelectric theory behind 'material on the brink'

Abstract:
Electron microscopy, conducted as part of the Shared Research Equipment (ShaRE) User Program at the Department of Energy's Oak Ridge National Laboratory, has led to a new theory to explain intriguing properties in a material with potential applications in capacitors and actuators.

ORNL microscopy inspires flexoelectric theory behind 'material on the brink'

Oak Ridge, TN | Posted on April 14th, 2012

A research team led by ORNL's Albina Borisevich examined thin films of bismuth samarium ferrite, known as BSFO, which exhibits unusual physical properties near its transition from one phase to another. BSFO holds potential as a lead-free substitute for lead zirconium titanate (PZT), a similar material currently used in dozens of technologies from sensors to ultrasound machines.

Materials such as BSFO and PZT are often called "materials on the brink" in reference to their enigmatic behavior, which is closely tied to the transition between two different phases. These phases are characterized by structural changes in the material that produce different electrical properties.

"The best properties of the material are found at this transition," Borisevich said. "However, there has been a lot of discussion about what exactly happens that leads to an enhancement of the material's properties."

Using scanning transmission electron microscopy, the team mapped the position of atoms in BSFO films to find what happens to the local structure at the transition between ferroelectric and antiferroelectric phases. The team's results are published in Nature Communications.

"We discovered that neither of the two dominant theories could describe the observed behavior at the atomic scale," Borisevich said.

Some theorists have proposed that the material forms a nanocomposite at the transition. In this case, the energy of the boundaries between phases would have to approach zero, but Borisevich's team found experimentally something entirely different: the boundary's energy was instead effectively negative.

"When the energy of boundary is negative, it means that the system wants to have as many boundaries as possible, but with atom sizes being finite, you can't increase it to infinity," Borisevich said. "So you have to stop at some short-period modulated structure, which is what happens here."

Based on its observations, the team concluded that the mechanism behind the observed behavior was linked to a relatively weak interaction called flexoelectricity.

"Flexoelectricity means that you bend a material and it polarizes," said ORNL coauthor Sergei Kalinin. "It's a property present in most ferroelectrics. The effect itself is not necessarily very strong on macroscopic scales, but with the right conditions, which are realized in nanoscale systems, it can produce very interesting consequences."

Borisevich adds that the team's approach can be used to investigate a variety of systems with similar phase boundaries, and she emphasizes the importance of mapping out materials at the atomic scale.

"In this particular case, electron microscopy is the only way to look at very local changes because this material is a periodic structure," she said. "The decisive atomic-scale information had been missing from the discussion."

Researchers include National Academy of Sciences of Ukraine's Eugene Eliseev and Anna Morozovska; University of New South Wales's Ching-Jung Cheng and Valanoor Nagarajan; National Chiao Tung University's Jiunn-Yuan Lin and Ying-Hao Chu; and University of Maryland's Daisuke Kan and Ichiro Takeuchi. The full paper is available online here: www.nature.com/ncomms/journal/v3/n4/full/ncomms1778.html.

This work was supported by DOE's Office of Science, which sponsors the Shared Research Equipment (ShaRE) User Facility.

####

About Oak Ridge National Laboratory
ORNL is managed by UT-Battelle for the Department of Energy's Office of Science. DOE's 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 science.energy.gov

For more information, please click here

Contacts:
Morgan McCorkle
Communications and Media Relations
865.574.7308

Copyright © Oak Ridge National Laboratory

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

News and information

Nanostructures Increase Corrosion Resistance in Metallic Body Implants May 24th, 2015

Iranian Scientists Use Magnetic Field to Transfer Anticancer Drug to Tumor Tissue May 24th, 2015

Basel physicists develop efficient method of signal transmission from nanocomponents May 23rd, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Visualizing How Radiation Bombardment Boosts Superconductivity: Atomic-level flyovers show how impact sites of high-energy ions pin potentially disruptive vortices to keep high-current superconductivity flowing May 23rd, 2015

Imaging

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Aspen Aerogels to Present at the Cowen and Company Technology, Media & Telecom Conference May 21st, 2015

Samtec, Global Provider of Interconnect Systems, Joins IRT Nanoelec Silicon Photonics Program May 21st, 2015

Laboratories

Visualizing How Radiation Bombardment Boosts Superconductivity: Atomic-level flyovers show how impact sites of high-energy ions pin potentially disruptive vortices to keep high-current superconductivity flowing May 23rd, 2015

Sandia researchers first to measure thermoelectric behavior by 'Tinkertoy' materials May 20th, 2015

Govt.-Legislation/Regulation/Funding/Policy

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Visualizing How Radiation Bombardment Boosts Superconductivity: Atomic-level flyovers show how impact sites of high-energy ions pin potentially disruptive vortices to keep high-current superconductivity flowing May 23rd, 2015

Nanotherapy effective in mice with multiple myeloma May 21st, 2015

Turn that defect upside down: Twin boundaries in lithium-ion batteries May 21st, 2015

Sensors

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Record high sensitive Graphene Hall sensors May 21st, 2015

Graphene enables tunable microwave antenna May 15th, 2015

Janusz Bryzek Joins MEMS Industry Group to Lead New TSensors Division - New Division will Focus on Accelerating Development of Emerging Ultra-high Volume Sensors Supporting Abundance, mHealth and IoT May 14th, 2015

Discoveries

Nanostructures Increase Corrosion Resistance in Metallic Body Implants May 24th, 2015

Iranian Scientists Use Magnetic Field to Transfer Anticancer Drug to Tumor Tissue May 24th, 2015

Basel physicists develop efficient method of signal transmission from nanocomponents May 23rd, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Announcements

Nanostructures Increase Corrosion Resistance in Metallic Body Implants May 24th, 2015

Iranian Scientists Use Magnetic Field to Transfer Anticancer Drug to Tumor Tissue May 24th, 2015

Basel physicists develop efficient method of signal transmission from nanocomponents May 23rd, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Tools

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Nanometrics Announces Live Webcast of Upcoming Investor and Analyst Day May 20th, 2015

Taking control of light emission: Researchers find a way of tuning light waves by pairing 2 exotic 2-D materials May 20th, 2015

DELMIC announces a workshop hosted by Phenom World on Integrated CLEM to be held on Wednesday June 24th at the Francis Crick Institute (Lincoln Inn Fields Laboratory). May 19th, 2015

Research partnerships

Supercomputer unlocks secrets of plant cells to pave the way for more resilient crops: IBM partners with University of Melbourne and UQ May 21st, 2015

Taking control of light emission: Researchers find a way of tuning light waves by pairing 2 exotic 2-D materials May 20th, 2015

Efficiency record for black silicon solar cells jumps to 22.1 percent: Aalto University's researchers improved their previous record by over 3 absolute percents in cooperation with Universitat Politècnica de Catalunya May 18th, 2015

Organic nanoparticles, more lethal to tumors: Carbon-based nanoparticles could be used to sensitize cancerous tumors to proton radiotherapy and induce more focused destruction of cancer cells, a new study shows May 18th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project