Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Unprecedented look at oxide interfaces reveals unexpected structures on atomic scale

05.08.2010
Thin layers of oxide materials and their interfaces have been observed in atomic resolution during growth for the first time by researchers at the Center for Nanophase Materials Sciences at the Department of Energy's Oak Ridge National Laboratory, providing new insight into the complicated link between their structure and properties.

"Imagine you suddenly had the ability to see in color, or in 3-D," said the CNMS's Sergei Kalinin. "That is how close we have been able to look at these very small interfaces."

The paper was published online in ACS Nano with ORNL's Junsoo Shin as lead author.

A component of magnetoelectronics and spintronics, oxide interfaces have the potential to replace silicon-based microelectronic devices and improve the power and memory retention of other electronic technologies.

However, oxide interfaces are difficult to analyze at the atomic scale because once the oxides are removed from their growth chamber they become contaminated. To circumvent this problem, ORNL researchers led by Art Baddorf built a unique system that allows scanning tunneling microscopy and low energy electron diffraction to capture images of the top layer of the oxide while in situ, or still in the vacuum chamber where the materials were grown by powerful laser pulses.

Many studies of similar oxide interfaces utilize a look from the side, typically achieved by aberration corrected scanning transmission electron microscopy (STEM). The ORNL team has used these cross-sectional images to map the oxide organization.

However, like a sandwich, oxide interfaces may be more than what they appear from the side. In order to observe the interactive layer of the top and bottom oxide, the group has used scanning tunneling microscopy to get an atomically resolved view of the surface of the oxide, and observed its evolution during the growth of a second oxide film on top.

"Instead of seeing a perfectly flat, square lattice that scientists thought these interfaces were before, we found a different and very complicated atomic ordering," said Baddorf. "We really need to reassess what we know about these materials."

Oxides can be used in different combinations to produce unique results. For instance, isolated, two oxides may be insulators but together the interface may become conductive. By viewing the atomic structure of one oxide, scientists can more effectively couple oxides to perform optimally in advanced technological applications such as transistors.

Kalinin says the correct application of these interface-based materials may open new pathways for development of computer processors and energy storage and conversion devices, as well as understanding basic physics controlling these materials.

"In the last 10 years, there has been only limited progress in developing beyond-silicon information technologies," Kalinin said. "Silicon has limitations that have been reached, and this has motivated people to explore other options."

Atomic resolution of interface structures during oxide growth will better enable scientists to identify defects of certain popular oxide combinations and could help narrow selections of oxides to spur new or more efficient commercial applications.

This research is supported by the U.S. Department of Energy, Office of Science.

The Center for Nanophase Materials Sciences at ORNL is one of the five DOE Nanoscale Science Research Centers supported by the DOE Office of Science, premier national user facilities for interdisciplinary research at the nanoscale. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE's Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge and Sandia and Los Alamos national laboratories. For more information about the DOE NSRCs, please visit http://nano.energy.gov.

ORNL is managed by UT-Battelle for the Department of Energy's Office of Science.

Katie Freeman | EurekAlert!
Further information:
http://nano.energy.gov

Further reports about: Energy Materials Science NSRCs Nanophase ORNL Science TV

More articles from Physics and Astronomy:

nachricht Gamma rays will reach beyond the limits of light
23.10.2017 | Chalmers University of Technology

nachricht Creation of coherent states in molecules by incoherent electrons
23.10.2017 | Tata Institute of Fundamental Research

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: Salmonella as a tumour medication

HZI researchers developed a bacterial strain that can be used in cancer therapy

Salmonellae are dangerous pathogens that enter the body via contaminated food and can cause severe infections. But these bacteria are also known to target...

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

3rd Symposium on Driving Simulation

23.10.2017 | Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

 
Latest News

Microfluidics probe 'cholesterol' of the oil industry

23.10.2017 | Life Sciences

Gamma rays will reach beyond the limits of light

23.10.2017 | Physics and Astronomy

The end of pneumonia? New vaccine offers hope

23.10.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>