Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


android tablet pc

Home > Press > UA Physicists Find Key to Long-Lived Metal Nanowires

Abstract:
Researchers predict that such nanotechnology will be the next Big Thing to revolutionize the computing, medical, power and other industries in coming decades.

UA Physicists Find Key to Long-Lived Metal Nanowires

August 25, 2005

By Lori Stiles

University of Arizona physicists have discovered what it takes to make metal 'nanowires' that last a long time. This is particularly important to the electronics industry, which hopes to use tiny wires -- that have diameters counted in tens of atoms -- in Lilputian electronic devices in the next 10 to 15 years.

Researchers predict that such nanotechnology will be the next Big Thing to revolutionize the computing, medical, power and other industries in coming decades.

Although researchers in Japan, the Netherlands, Spain, Brazil and the United States have had some success at making nanowires -- extremely small filaments that transport electrons -- the wires don't last long except at low temperatures.

University of Arizona - nanowire
This illustration represents a metallic quantum wire before it's stretched to the breaking point. (Illustration: Courtesy of Charles Stafford). Copyright University of Arizona

What researchers need are robust nanowires that will take repeated use without failing at room temperature and higher.

UA post-doctoral associate Jerome Buerki and physics Professors Charles Stafford and Daniel Stein developed a theory that explains why nanowires thin away to nothing at non-zero temperatures. Energy fluctuations in a nanowire at higher temperatures create a collective motion, or "soliton," among atoms in the wire. As each of these kink-like structures propagates from one end of the wire to the other, the wire thins.

Stafford has posted movies that show this phenomenon on his Web page. The movie was made by the Takayanagi group at the Tokyo Institute of Technology.

"Our theory makes one very simple prediction, which is that the energy barrier that creates these kinks depends, very simply, on the square root of the surface tension of the wire," Stafford said. "That's quite counterintuitive, because naively you'd think that surface tension should actually make the filament unstable. But the larger the surface tension, the more stable the wire, regardless of the radius of the wire."

Creation of solitons, or kinks, in the wire depends on two competing forces - the surface tension and a quantum force that holds the wire together, Stafford explained. "It just so happens that the competition between those two forces leads to a kind of universal energy barrier which goes as the square root of the surface tension."

The discovery explains why experimentalists have had more luck at making longer-lived nanowires using such noble metals as gold and silver rather than sodium or other alkali metals. According to the UA physicists' theory, copper is the best metal for making nanowires because it has the largest natural surface tension of the nanowire metals.

"The hardest thing with developing nanowires, I think, is how to fabricate them in a controlled way," Stafford said. "The movies show how researchers can fabricate one tiny wire, but that's not connecting many such wires, or connecting them to make a circuit.

"But at least, our work says that these wires are very stable, and that we understand exactly how stable they are. I think that can give people confidence to move ahead with trying to do something practical with them."

The research, funded by the National Science Foundation, will be published this week in Physical Review Letters. The article, "Theory of Metastability in Simple Metal Nanowires," appears online here.

####
Contacts:
Charles Stafford
520-626-4260
stafford@physics.arizona.edu

Jerome Buerki
520-626-1546
buerki@physics.arizona.edu

Daniel L. Stein
dls@physics.arizona.edu

Related Web sites
Takayanagi movie
Physical Review Letters online

Copyright University of Arizona

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

Possible Futures

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Superconducting circuits, simplified: New circuit design could unlock the power of experimental superconducting computer chips October 18th, 2014

Nanocoatings Market By Product Is Expected To Reach USD 8.17 Billion By 2020: Grand View Research, Inc. October 15th, 2014

Perpetuus Carbon Group Receives Independent Verification of its Production Capacity for Graphenes at 140 Tonnes per Annum: Perpetuus Becomes the First Manufacturer in the Sector to Allow Third Party Audit October 7th, 2014

Nanoelectronics

Materials for the next generation of electronics and photovoltaics: MacArthur Fellow develops new uses for carbon nanotubes October 21st, 2014

Crystallizing the DNA nanotechnology dream: Scientists have designed the first large DNA crystals with precisely prescribed depths and complex 3D features, which could create revolutionary nanodevices October 20th, 2014

Imaging electric charge propagating along microbial nanowires October 20th, 2014

Future computers could be built from magnetic 'tornadoes' October 14th, 2014

Announcements

Special UO microscope captures defects in nanotubes: University of Oregon chemists provide a detailed view of traps that disrupt energy flow, possibly pointing toward improved charge-carrying devices October 21st, 2014

Super stable garnet ceramics may be ideal for high-energy lithium batteries October 21st, 2014

Could I squeeze by you? Ames Laboratory scientists model molecular movement within narrow channels of mesoporous nanoparticles October 21st, 2014

Detecting Cancer Earlier is Goal of Rutgers-Developed Medical Imaging Technology: Rare earth nanocrystals and infrared light can reveal small cancerous tumors and cardiovascular lesions October 21st, 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