Subscribe free to our newsletters via your
. 24/7 Space News .




CARBON WORLDS
ORNL microscopy reveals 'atomic antenna' behavior in graphene
by Staff Writers
Oak Ridge TN (SPX) Feb 03, 2012


Electron microscopy at Oak Ridge National Laboratory has demonstrated that silicon atoms (seen in white) can act like "atomic antennae" in graphene and transmit an electronic signal at the atomic scale.

Atomic-level defects in graphene could be a path forward to smaller and faster electronic devices, according to a study led by researchers at the Department of Energy's Oak Ridge National Laboratory.

With unique properties and potential applications in areas from electronics to biodevices, graphene, which consists of a single sheet of carbon atoms, has been hailed as a rising star in the materials world.

Now, an ORNL study published in Nature Nanotechnology suggests that point defects, composed of silicon atoms that replace individual carbon atoms in graphene, could aid attempts to transfer data on an atomic scale by coupling light with electrons.

"In this proof of concept experiment, we have shown that a tiny wire made up of a pair of single silicon atoms in graphene can be used to convert light into an electronic signal, transmit the signal and then convert the signal back into light," said coauthor Juan-Carlos Idrobo, who holds a joint appointment at ORNL and Vanderbilt University.

An ORNL-led team discovered this novel behavior by using aberration-corrected scanning transmission electron microscopy to image the plasmon response, or optical-like signals, of the point defects.

The team's analysis found that the silicon atoms act like atomic-sized antennae, enhancing the local surface plasmon response of graphene, and creating a prototypical plasmonic device.

"The idea with plasmonic devices is that they can convert optical signals into electronic signals," Idrobo said.

"So you could make really tiny wires, put light in one side of the wire, and that signal will be transformed into collective electron excitations known as plasmons. The plasmons will transmit the signal through the wire, come out the other side and be converted back to light."

Although other plasmonic devices have been demonstrated, previous research in surface plasmons has been focused primarily on metals, which has limited the scale at which the signal transfer occurs.

"When researchers use metal for plasmonic devices, they can usually only get down to 5 - 7 nanometers," said coauthor Wu Zhou. "But when you want to make things smaller, you always want to know the limit. Nobody thought we could get down to a single atom level."

In-depth analysis at the level of a single atom was made possible through the team's access to an electron microscope that is part of ORNL's Shared Research Equipment (ShaRE) User Facility.

"It is the one of only a few electron microscopes in the world that we can use to look at and study materials and obtain crystallography, chemistry, bonding, optical and plasmon properties at the atomic scale with single atom sensitivity and at low voltages," Idrobo said.

"This is an ideal microscope for people who want to research carbon-based materials, such as graphene."

In addition to its microscopic observations, the ORNL team employed theoretical first-principles calculations to confirm the stability of the observed point defects.

.


Related Links
Oak Ridge National Laboratory
Carbon Worlds - where graphite, diamond, amorphous, fullerenes meet






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





CARBON WORLDS
New form of graphene could prevent electronics from overheating and revolutionize thermal management
Austin TX (SPX) Jan 13, 2012
A new form of graphene created by researchers at The University of Texas at Austin could prevent laptops and other electronics from overheating, ultimately, overcoming one of the largest hurdles to building smaller and more powerful electronic devices. The research team, which includes colleagues at The University of Texas at Dallas, the University of California-Riverside and Xiamen Univer ... read more


CARBON WORLDS
NASA Mission Returns First Video From Lunar Far Side

A Moon Colony by 2020

U.S. Presidential Hopeful Promises Moon Base by 2020

Moon looms bright over Republican debate

CARBON WORLDS
U.K. study: Mars surface too dry for life

Radio Doppler Tracking Continues at Cape York

Russia May Repeat Mars-500 Simulation on Space Station

A dark spot on Mars - Syrtis Major

CARBON WORLDS
NASA Receives Final NRC Report On Space Technology Roadmaps

Final Call to Register and Win Suborbital Research Flight

Northrop Grumman Develops Solar Electric Propulsion Flight Concepts for Future Space Missions

How NASA Solved a 100 Million Dollar Problem for Five Bucks

CARBON WORLDS
China's satellite navigation sector annual output predicted to reach 35 bln USD in 2015

China plans to launch 21 rockets, 30 satellites this year

Shenzhou 9 Behind the Curtain

China Plans to Launch 30 Satellites in 2012

CARBON WORLDS
Next manned ISS mission to launch May 15: Russia

Capsule failure delays ISS crew mission

Russia to postpone next manned space launch: official

Russia will replace Soyuz for next ISS mission: source

CARBON WORLDS
SpaceX flight to ISS could be late March: NASA

Feb 13 set as new date for Europe's Vega rocket

Launch of Proton-M with Dutch Satellite Postponed

First Vega rocket assembled on launch pad

CARBON WORLDS
Russia to Start Own Search for Extrasolar Planets

Planets Circling Around Twin Suns

Scientists help define structure of exoplanets

Fourth potentially habitable planet is discovered

CARBON WORLDS
Smart paint could revolutionize structural safety

LockMart MUOS Satellite Encapsulated In Launch Vehicle Payload Fairing

Green light for Malaysia rare earths plant

Space Radiation Blamed for Phobos-Grunt Crash




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. 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 Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement