Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UA Physicists Find Key to Long-Lived Metal Nanowires

25.08.2005


This illustration represents a metallic quantum wire before it’s stretched to the breaking point. (Illustration: Courtesy of Charles Stafford)


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.



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, http://www.physics.arizona.edu/~stafford/necking.htmlThe 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 at http://link.aps.org/abstract/PRL/v95/390601.

Lori Stiles | EurekAlert!
Further information:
http://www.arizona.edu

More articles from Physics and Astronomy:

nachricht Innovative LED High Power Light Source for UV
22.06.2017 | Omicron - Laserage Laserprodukte GmbH

nachricht Spin liquids − back to the roots
22.06.2017 | Universität Augsburg

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

Im Focus: Optoelectronic Inline Measurement – Accurate to the Nanometer

Germany counts high-precision manufacturing processes among its advantages as a location. It’s not just the aerospace and automotive industries that require almost waste-free, high-precision manufacturing to provide an efficient way of testing the shape and orientation tolerances of products. Since current inline measurement technology not yet provides the required accuracy, the Fraunhofer Institute for Laser Technology ILT is collaborating with four renowned industry partners in the INSPIRE project to develop inline sensors with a new accuracy class. Funded by the German Federal Ministry of Education and Research (BMBF), the project is scheduled to run until the end of 2019.

New Manufacturing Technologies for New Products

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

A new technique isolates neuronal activity during memory consolidation

22.06.2017 | Life Sciences

Plant inspiration could lead to flexible electronics

22.06.2017 | Materials Sciences

A rhodium-based catalyst for making organosilicon using less precious metal

22.06.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>