Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Just Scratching the Surface: New Technique Maps Nanomaterials as They Grow

06.11.2008
Researchers at Rensselaer Polytechnic Institute have developed a measurement technique that will help scientists and companies map nanomaterials as they grow. The discovery could help create superior nanotechnologies and lead to the development of more efficient solar panels and increased magnetic data storage.

“Since we discovered this technique, we have been trying to get the word out to the nanoscience and nanotechnology research community,” said professor and head of physics, applied physics, and astronomy Gwo-Ching Wang, who helped discover the technique.


Rensselaer/Gwo-Ching Wang
The new technique maps the surface of a nanomaterial as it grows. In this figure, a surface pole figure has been created for magnesium nanoblades.

“It is inexpensive because it uses existing technology and vastly increases the rate of discovery by giving researchers a very clear picture of how to perfect and duplicate the growth of a new nanomaterial without spending months characterizing its structures after the growth.”

The approach is based on a commonly used technique known as reflection high-energy electron diffraction, or RHEED. The traditional RHEED system creates an interference pattern of the surface of the nanomaterial. The pattern contains only partial information of the surface and is only a snapshot in time of the growing surface. The researchers modified the traditional RHEED technique by rotating the substrate on which the nanomaterial is being grown. This gives them a diagram containing the complete information on the crystal orientation distribution of the growing surface.

The new technique is different from other common techniques such as X-rays because it monitors the surface structure of the material as it grows. X-ray and other technologies measure the entire material, from the tip of the new growth straight through the substrate that the material is growing on. The new RHEED technique shows the growth of only a few nanometers of a material at a time.

“The creation of a surface crystal orientation diagram is particularly important for revealing the nature of the growth of nanostructures such as nanodots, nanorods, and nanoblades, which have strong energy and data storage capabilities, but their orientation can change dramatically over time,” Wang said. These changes in crystal orientation and morphology of the material can substantially increase or decrease the material’s efficiency. It also makes their use in consumer products difficult because of their unpredictability, according to Wang.

Wang views solar energy materials as one of the most important applications for the new technique. The most efficient solar panels on the market are comprised of single crystal materials, meaning that the material is one unbroken material with no grain boundaries. Grain boundaries in a nanomaterial cause huge decreases in energy-conversion capabilities. But, single crystal solar cells are so costly that they could never be widely used on the consumer market, Wang said. So, many scientists and solar cell companies are working to create polycrystalline materials that grow in such a way that they transfer light into electricity similar to a single crystal material despite having grain boundaries. These materials are also much less expensive, according to Wang.

“The problem with creating high-quality polycrystalline materials is that you need a powerful technique to monitor them in nanoscale dimensions as they grow so you can quickly work on recreating the material to maximize its efficiency,” Wang said. “The new RHEED technique really allows researchers to create a material, see how it formed, and then turn around and recreate the most ideal version of that material without extensive experimentations.”

Wang was joined in her research by Toh-Ming Lu, professor of physics, applied physics, and astronomy, and postdoctoral research associate Fu Tang. Together they have presented their findings within the Proceedings of SPIE and the Journal of Physics D: Applied Physics as well as at conferences around the world including the American Vacuum Society 55th International Symposium and Exhibition on Oct. 23 and before representatives from the Department of Energy on Oct. 31.

“Everywhere we go to present these findings, people have become more and more excited about the possibilities that it opens up for them in their own research,” she said.

Gabrielle DeMarco | Newswise Science News
Further information:
http://www.rpi.edu

More articles from Materials Sciences:

nachricht New biomaterial could replace plastic laminates, greatly reduce pollution
21.09.2017 | Penn State

nachricht Stopping problem ice -- by cracking it
21.09.2017 | Norwegian University of Science and Technology

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The pyrenoid is a carbon-fixing liquid droplet

Plants and algae use the enzyme Rubisco to fix carbon dioxide, removing it from the atmosphere and converting it into biomass. Algae have figured out a way to increase the efficiency of carbon fixation. They gather most of their Rubisco into a ball-shaped microcompartment called the pyrenoid, which they flood with a high local concentration of carbon dioxide. A team of scientists at Princeton University, the Carnegie Institution for Science, Stanford University and the Max Plank Institute of Biochemistry have unravelled the mysteries of how the pyrenoid is assembled. These insights can help to engineer crops that remove more carbon dioxide from the atmosphere while producing more food.

A warming planet

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Rainbow colors reveal cell history: Uncovering β-cell heterogeneity

22.09.2017 | Life Sciences

Penn first in world to treat patient with new radiation technology

22.09.2017 | Medical Engineering

Calculating quietness

22.09.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>