Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

No Small Measure: Origins of Nanorod Diameter Discovered

23.03.2009
A new study answers a key question at the very heart of nanotechnology: Why are nanorods so small?

Researchers at Rensselaer Polytechnic Institute have discovered the origins of nanorod diameter, demonstrating that the competition and collaboration among various mechanisms of atomic transport hold the key to nanorod size.

The researchers say it is the first study to identify the fundamental reasons why nearly all nanorods have a diameter on the order of 100 nanometers.

“Scientists have been fabricating nanorods for decades, but no one has ever answered the question, ‘Why is that possible?’” said Hanchen Huang, professor in Rensselaer’s Department of Mechanical, Aerospace, and Nuclear Engineering, who led the study. “We have used computer modeling to identify, for the first time, the fundamental reasons behind nanorod diameter. With this new understanding, we should be able to better control nanorods, and therefore design better devices.”

Results of the study, titled “A characteristic length scale of nanorods diameter during growth,” were recently published in the journal Physical Review Letters.

When fabricating nanorods, atoms are released at an oblique angle onto a surface, and the atoms accumulate and grow into nanorods about 100 nanometers in diameter. A nanometer is one billionth of a meter in length.

The accumulating atoms form small layers. After being deposited onto a layer, it takes varying amounts of energy for atoms to travel or “step” downward to a lower layer, depending on the step height. In a previous study, Huang and colleagues calculated and identified these precise energy requirements. As a result, the researchers discovered the fundamental reason nanorods grow tall: as atoms are unable to step down to the next lowest layer, they begin to stack up and grow higher.

It is the cooperation and competition of atoms in this process of multi-layer diffusion that accounts for the fundamental diameter of nanorods, Huang shows in the new study. The rate at which atoms are being deposited onto the surface, as well as the temperature of the surface, also factor into the equation.

“Surface steps are effective in slowing down the mass transport of surface atoms, and aggregated surface steps are even more effective,” Huang said. “This extra effectiveness makes the diameter of nanorods around 100 nanometers; without it the diameter would go up to 10 microns.”

Beyond advancing scientific theory, Huang said the discovery could have implications for developing photonic materials and fuel cell catalysts.

Huang co-authored the paper with Rensselaer Research Scientist Longguang Zhou.

Funding for this research was provided by the U.S. Department of Energy Office of Basic Energy Science.

Visit Huang’s Web site for more information on his nanotechnology and materials research.

Contact: Michael Mullaney
Phone: (518) 276-6161
E-mail: mullam@rpi.edu

Michael Mullaney | EurekAlert!
Further information:
http://www.rpi.edu

More articles from Physics and Astronomy:

nachricht Engineering team images tiny quasicrystals as they form
18.08.2017 | Cornell University

nachricht Astrophysicists explain the mysterious behavior of cosmic rays
18.08.2017 | Moscow Institute of Physics and Technology

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: Fizzy soda water could be key to clean manufacture of flat wonder material: Graphene

Whether you call it effervescent, fizzy, or sparkling, carbonated water is making a comeback as a beverage. Aside from quenching thirst, researchers at the University of Illinois at Urbana-Champaign have discovered a new use for these "bubbly" concoctions that will have major impact on the manufacturer of the world's thinnest, flattest, and one most useful materials -- graphene.

As graphene's popularity grows as an advanced "wonder" material, the speed and quality at which it can be manufactured will be paramount. With that in mind,...

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Call for Papers – ICNFT 2018, 5th International Conference on New Forming Technology

16.08.2017 | Event News

Sustainability is the business model of tomorrow

04.08.2017 | Event News

Clash of Realities 2017: Registration now open. International Conference at TH Köln

26.07.2017 | Event News

 
Latest News

A Map of the Cell’s Power Station

18.08.2017 | Life Sciences

Engineering team images tiny quasicrystals as they form

18.08.2017 | Physics and Astronomy

Researchers printed graphene-like materials with inkjet

18.08.2017 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>