Space Industry and Business News  





.
TECH SPACE
Graphene Grains Make Atom-Thick Patchwork Quilts

File image.
by Staff Writers
Ithaca NY (SPX) Jan 06, 2011
Cornell University researchers have unveiled striking, atomic-resolution details of what graphene "quilts" look like at the boundaries between patches, and have uncovered key insights into graphene's electrical and mechanical properties.

Researchers focused on graphene - a one atom-thick sheet of carbon atoms bonded in a crystal lattice like a honeycomb or chicken wire - because of its electrical properties and potential to improve everything from solar cells to cell phone screens.

But graphene doesn't grow in perfect sheets. Rather, it develops in pieces that resemble patchwork quilts, where the honeycomb lattice meets up imperfectly. These "patches" meet at grain boundaries, and scientists had wondered whether these boundaries would allow the special properties of a perfect graphene crystal to transfer to the much larger quilt-like structures.

To study the material, the researchers grew graphene membranes on a copper substrate (a method devised by another group) but then conceived a novel way to peel them off as free-standing, atom-thick films.

Then with diffraction imaging electron microscopy, they imaged the graphene by seeing how electrons bounced off at certain angles, and using a color to represent that angle. By overlaying different colors according to how the electrons bounced, they created an easy, efficient method of imaging the graphene grain boundaries according to their orientation. And as a bonus, their pictures took an artistic turn, reminding the scientists of patchwork quilts.

"You don't want to look at the whole quilt by counting each thread. You want to stand back and see what it looks like on the bed. And so we developed a method that filters out the crystal information in a way that you don't have to count every atom," said David Muller, professor of applied and engineering physics and co-director of the Kavli Institute at Cornell for Nanoscale Science.

Muller conducted the work with Paul McEuen, professor of physics and director of the Kavli Institute, and Kavli member Jiwoong Park, assistant professor of chemistry and chemical biology.

Further analysis revealed that growing larger grains (bigger patches) didn't improve the electrical conductivity of the graphene, as was previously thought by materials scientists. Rather, it is impurities that sneak into the sheets that make the electrical properties fluctuate. This insight will lead scientists closer to the best ways to grow and use graphene.

The work was supported by the National Science Foundation through the Cornell Center for Materials Research and the Nanoscale Science and Engineering Initiative. The paper's other contributors were: Pinshane Huang, Carlos Ruiz-Vargas, Arend van der Zande, William Whitney, Mark Levendorf, Shivank Garg, JonathanAlden and Ye Zhu, all from Cornell; Joshua Kevek, Oregon State University and Caleb Hustedt, Brigham Young University.




Share This Article With Planet Earth
del.icio.usdel.icio.us DiggDigg RedditReddit
YahooMyWebYahooMyWeb GoogleGoogle FacebookFacebook



Related Links
Cornell University
Space Technology News - Applications and Research



Tempur-Pedic Mattress Comparison

Newsletters :: SpaceDaily Express :: SpaceWar Express :: TerraDaily Express :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News
TECH SPACE
Recycled Haitian Concrete Can Be Safe, Strong And Less Expensive
Westerville OH (SPX) Jan 05, 2011
Nearly one year after a 7.0-magnitude earthquake rocked the Republic of Haiti, engineering and concrete experts at Georgia Tech report that concrete and other debris in Port-au-Prince can be safely and inexpensively recycled into strong new construction material. In a paper published in the Bulletin of the American Ceramic Society, researchers Reginald R. DesRoches, Kimberly E. Kurtis and ... read more

.
Get Our Free Newsletters Via Email
  


TECH SPACE
Developing Bio-Based Polymers That Heal Cracks

Supercomputer Unravels Structures In DVD Materials

Motorola Xoom tablet crowned best CES gadget

Google's Android stars at electronics show

TECH SPACE
IBCS Completes Warfighter-Centered Design Exercises

Arianespace Will Orbit Sicral 2 Milcomms Satellites

Codan Receives JITC Certification For 2110 HF Manpack

Northrop Grumman Bids for Marine Corps Common Aviation CnC

TECH SPACE
ISRO To Launch Two Communication Satellites This Year

Arianespace Will Have A Record Year Of Launch Activity In 2011

2011: The Arianespace Family Takes Shape

ISRO To Launch Singapore's First Satellite In Orbit In February

TECH SPACE
ISRO To Implement Regional Navigation Satellite System

Networks Of Up To 2 Million Cells Now Supported By GeoLENs Location Platform

Software Will Take Half Of The Total Nav Market By 2016

Garmin Has A GPS Device For Everyone

TECH SPACE
China completes prototype of stealth fighter: reports

France 'confident' of winning Brazil plane contract

Clariant resumes aircraft de-icer output after winter halt

Cathay makes pay offer to pilots: report

TECH SPACE
Greenpeace ranks 'greenest' electronics

Better Control Of Building Blocks For Quantum Computer

S.Korea's Hynix says chip price slump will hit Q4 profit

Iridium Memories

TECH SPACE
Google illegally gathered data in S.Korea: police

Sat-nav turtles go on trans-ocean trek

Cyclone Tasha Adds To Severe Flooding Over Eastern Australia

Tidal Flats And Channels, Long Island, Bahamas

TECH SPACE
Kenya bans plastic bags

Oceanic "Garbage Patch" Not Nearly As Big As Portrayed In Media

British local authorities rubbished over trash backlog

Britain's rubbish: cold and holidays pile up trash


The content herein, unless otherwise known to be public domain, are Copyright 1995-2010 - SpaceDaily. AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement