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 A better way to weigh millions of solitary stars
15.12.2017 | Vanderbilt University

nachricht A chip for environmental and health monitoring
15.12.2017 | Friedrich-Alexander-Universität Erlangen-Nürnberg

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: First-of-its-kind chemical oscillator offers new level of molecular control

DNA molecules that follow specific instructions could offer more precise molecular control of synthetic chemical systems, a discovery that opens the door for engineers to create molecular machines with new and complex behaviors.

Researchers have created chemical amplifiers and a chemical oscillator using a systematic method that has the potential to embed sophisticated circuit...

Im Focus: Long-lived storage of a photonic qubit for worldwide teleportation

MPQ scientists achieve long storage times for photonic quantum bits which break the lower bound for direct teleportation in a global quantum network.

Concerning the development of quantum memories for the realization of global quantum networks, scientists of the Quantum Dynamics Division led by Professor...

Im Focus: Electromagnetic water cloak eliminates drag and wake

Detailed calculations show water cloaks are feasible with today's technology

Researchers have developed a water cloaking concept based on electromagnetic forces that could eliminate an object's wake, greatly reducing its drag while...

Im Focus: Scientists channel graphene to understand filtration and ion transport into cells

Tiny pores at a cell's entryway act as miniature bouncers, letting in some electrically charged atoms--ions--but blocking others. Operating as exquisitely sensitive filters, these "ion channels" play a critical role in biological functions such as muscle contraction and the firing of brain cells.

To rapidly transport the right ions through the cell membrane, the tiny channels rely on a complex interplay between the ions and surrounding molecules,...

Im Focus: Towards data storage at the single molecule level

The miniaturization of the current technology of storage media is hindered by fundamental limits of quantum mechanics. A new approach consists in using so-called spin-crossover molecules as the smallest possible storage unit. Similar to normal hard drives, these special molecules can save information via their magnetic state. A research team from Kiel University has now managed to successfully place a new class of spin-crossover molecules onto a surface and to improve the molecule’s storage capacity. The storage density of conventional hard drives could therefore theoretically be increased by more than one hundred fold. The study has been published in the scientific journal Nano Letters.

Over the past few years, the building blocks of storage media have gotten ever smaller. But further miniaturization of the current technology is hindered by...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

See, understand and experience the work of the future

11.12.2017 | Event News

Innovative strategies to tackle parasitic worms

08.12.2017 | Event News

AKL’18: The opportunities and challenges of digitalization in the laser industry

07.12.2017 | Event News

 
Latest News

Engineers program tiny robots to move, think like insects

15.12.2017 | Power and Electrical Engineering

One in 5 materials chemistry papers may be wrong, study suggests

15.12.2017 | Materials Sciences

New antbird species discovered in Peru by LSU ornithologists

15.12.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>