Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Just one nanosecond: Clocking events at the nanoscale

22.05.2006


As scientists and engineers build devices at smaller and smaller scales, grasping the dynamics of how materials behave when they are subjected to electrical signals, sound and other manipulations has proven to be beyond the reach of standard scientific techniques. But now a team of University of Wisconsin-Madison researchers has found a way to time such effects at the nanometer scale, in essence clocking the movements of atoms as they are manipulated using electric fields.

The accomplishment, reported in the most recent edition (May 12, 2006) of the journal Physical Review Letters, is important because it gives scientists a way to probe another dimension of a material’s structure at the scale of nanometers. Adding the dimension of time to their view of the nanoworld promises to enhance the ability to develop materials for improved memory applications in microelectronics of all kinds, among other things.

"Now we have a tool to look inside a device and see how it works at the spatial scale of nanometers and the time scale of nanoseconds," says Alexei Grigoriev, a UW-Madison postdoctoral fellow and the lead author of the Physical Review Letters paper.



With the advent of nanotechnology, the ability to make devices and products on a scale measured in atoms has mushroomed. Already, products with elements fabricated at the nanoscale are on the market, and scientists continue to hone the technology, which has potential applications in areas ranging from digital electronics to toothpaste.

The traditional tools of nanotechnology -- the atomic force microscope and the scanning tunneling microscope -- enable scientists to see atoms, but not their response to events, which at that scale occur on the order of a billionth of a second or less.

The ability to time events that occur in materials used in nanofabrication means that scientists can now view dynamic events at the atomic scale in key materials as they unfold. That ability, in turn, promises a more detailed understanding -- and potential manipulation -- of the properties of those materials.

The Wisconsin work was accomplished using Argonne National Laboratory’s Advanced Photon Source, a synchrotron light source capable of generating very tightly focused beams of X-rays. The Wisconsin researchers, in a group led by materials science and engineering Professor Paul Evans, focused a beam of X-rays on a thin film of a ferroelectric material grown by another Wisconsin group led by materials science and engineering Professor Chang-Beom Eom.

The X-rays, according to Grigoriev, are delivered to the sample in fast pulses over an area no larger than hundreds of nanometers, one ten-millionth of a meter.

Ferroelectric materials respond to electric fields by expanding or contracting their crystal lattice structures. Ferroelectric materials also exhibit the property of remnant polarization, where atoms are rearranged in response to electrical signals. This property allows tiny ferroelectric crystals to be used as elements of digital memories.

"Physically, the atoms switch position," Grigoriev explains. "And as devices are pushed to smaller sizes, they must switch in extremely short times. It requires new tools to see those dynamics."

Using the X-rays from the Advanced Photon Source and measuring how the X-rays were reflected as the atoms in the material switched positions, the Wisconsin researchers were able to clock the event.

As a material is subjected to the X-rays and the electrical signals, "you can see in time how the crystal structure (of the material) changes as the switching polarization propagates through the lattice," Grigoriev explains.

The technique developed by Evans, Grigoriev and their colleagues is a combination of two existing techniques, making the technology easily accessible to science. It might also be applied to studies of phenomena such as magnetism and heat dissipation in microelectronic structures.

Alexei Grigoriev | EurekAlert!
Further information:
http://www.wisc.edu

More articles from Physics and Astronomy:

nachricht Individualized fiber components for the world market
23.06.2017 | Laser Zentrum Hannover e.V.

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

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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

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)...

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

Can we see monkeys from space? Emerging technologies to map biodiversity

23.06.2017 | Information Technology

Understanding animal social networks can aid wildlife conservation

23.06.2017 | Ecology, The Environment and Conservation

A new technique isolates neuronal activity during memory consolidation

22.06.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>