Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > ORNL scientists help explain graphene mystery

ORNL simulations demonstrate how loops (seen above in blue) between graphene layers can be minimized using electron irradiation (bottom).
ORNL simulations demonstrate how loops (seen above in blue) between graphene layers can be minimized using electron irradiation (bottom).

Abstract:
Nanoscale simulations and theoretical research performed at the Department of Energy's Oak Ridge National Laboratory are bringing scientists closer to realizing graphene's potential in electronic applications.

ORNL scientists help explain graphene mystery

Oak Ridge, TN | Posted on August 24th, 2010

A research team led by ORNL's Bobby Sumpter, Vincent Meunier and Eduardo Cruz-Silva has discovered how loops develop in graphene, an electrically conductive high-strength low-weight material that resembles an atomic-scale honeycomb.

Structural loops that sometimes form during a graphene cleaning process can render the material unsuitable for electronic applications. Overcoming these types of problems is of great interest to the electronics industry.

"Graphene is a rising star in the materials world, given its potential for use in precise electronic components like transistors or other semiconductors," said Bobby Sumpter, a staff scientist at ORNL.

The team used quantum molecular dynamics to simulate an experimental graphene cleaning process, as discussed in a paper published in Physical Review Letters. Calculations performed on ORNL supercomputers pointed the researchers to an overlooked intermediate step during processing.

Imaging with a transmission electron microscope, or TEM, subjected the graphene to electron irradiation, which ultimately prevented loop formation. The ORNL simulations showed that by injecting electrons to collect an image, the electrons were simultaneously changing the material's structure.

"Taking a picture with a TEM is not merely taking a picture," Sumpter said. "You might modify the picture at the same time that you're looking at it."

The research builds on findings discussed in a 2009 Science paper (Jia et al.), where Meunier and Sumpter helped demonstrate a process that cleans graphene edges by running a current through the material in a process known as Joule heating. Graphene is only as good as the uniformity or cleanliness of its edges, which determine how effectively the material can transmit electrons. Meunier said the ability to efficiently clean graphene edges is crucial to using the material in electronics.

"Imagine you have a fancy sports car, but then you realize it has square wheels. What good is it? That's like having jagged edges on graphene," Meunier said.

Recent experimental studies have shown that the Joule heating process can lead to undesirable loops that connect different graphene layers. The PRL paper provides an atomistic understanding of how electron irradiation from a transmission electron microscope affects the graphene cleaning process by preventing loop formation.

"We can clean the edges, and not only that, we're able to understand why we can clean them," Meunier said.

The research team included scientists from Massachusetts Institute of Technology, Universite Catholique de Louvain and Carlos III University of Madrid. Sumpter and Meunier are members of ORNL's Computer Science and Mathematics division with appointments in the Nanomaterials Theory Institute within the Center for Nanophase Materials Sciences. Cruz-Silva is a post-doctoral researcher at ORNL.

Part of this work was supported by the Center for Nanophase Materials Sciences (CNMS) at ORNL. 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 and Sandia and Los Alamos national laboratories. For more information about the DOE NSRCs, please visit nano.energy.gov. ORNL is managed by UT-Battelle for the Department of Energy's Office of Science.

####

For more information, please click here

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

'Exotic' material is like a switch when super thin April 18th, 2014

Innovative strategy to facilitate organ repair April 18th, 2014

Oxford Instruments Asylum Research Introduces the MFP-3D InfinityTM AFM Featuring Powerful New Capabilities and Stunning High Performance April 18th, 2014

Conductive Inks: booming to $2.8 billion by 2024 April 17th, 2014

Govt.-Legislation/Regulation/Funding/Policy

'Exotic' material is like a switch when super thin April 18th, 2014

Innovative strategy to facilitate organ repair April 18th, 2014

Novel stapled peptide nanoparticle combination prevents RSV infection, study finds April 17th, 2014

INSCX™ exchange to present Exchange trade reporting mechanism for engineered nanomaterials (NMs) to UK regulation agencies, insurers and upstream/downstream users April 17th, 2014

Possible Futures

Virus structure inspires novel understanding of onion-like carbon nanoparticles April 10th, 2014

Local girl does good March 22nd, 2014

Surface Characteristics Influence Cellular Growth on Semiconductor Material March 12th, 2014

The "Tipping Point" February 12th, 2014

Nanotubes/Buckyballs

Effects of Carbon Nanotubes Studied on Pregnant Mothers April 12th, 2014

Nanotech Business Review 2013-2014 April 9th, 2014

Scientists Succeed in Simultaneous Determination of Acetaminophen, Codeine in Drug Samples April 9th, 2014

Rebar technique strengthens case for graphene: Rice University lab makes hybrid nanotube-graphene material that promises to simplify manufacturing April 7th, 2014

Announcements

'Exotic' material is like a switch when super thin April 18th, 2014

Innovative strategy to facilitate organ repair April 18th, 2014

Oxford Instruments Asylum Research Introduces the MFP-3D InfinityTM AFM Featuring Powerful New Capabilities and Stunning High Performance April 18th, 2014

Transparent Conductive Films and Sensors Are Hot Segments in Printed Electronics: Start-ups in these fields show above-average momentum, while companies working on emissive displays such as OLED are fading, Lux Research says April 17th, 2014

Research partnerships

Novel stapled peptide nanoparticle combination prevents RSV infection, study finds April 17th, 2014

Scientists Capture Ultrafast Snapshots of Light-Driven Superconductivity: X-rays reveal how rapidly vanishing 'charge stripes' may be behind laser-induced high-temperature superconductivity April 16th, 2014

Scalable CVD process for making 2-D molybdenum diselenide: Rice, NTU scientists unveil CVD production for coveted 2-D semiconductor April 8th, 2014

Carbon nanotubes grow in combustion flames April 1st, 2014

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







© Copyright 1999-2014 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE