Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Superconductivity-Related Materials Retain Shape but Change Properties Under Strain

02.09.2011
Finding opens path for new materials and devices

A University of Arkansas physicist and his colleagues have found that ultra-thin films of superconductors and related materials don’t lose their fundamental properties when built under strain when built as atomically thin layers, an important step towards achieving artificially designed room temperature superconductivity. This ability will allow researchers to create new types of materials and properties and enable exotic electronic phases in ultra-thin films.

Jak Chakhalian, University of Arkansas professor of physics, and his colleagues reported their findings in Physical Review Letters.

Room temperature superconductivity would change the world’s economy, Chakhalian contends. To start, superconductors can carry electricity without losing energy to heat during transmission the way all of today’s materials do. Today’s power grid loses almost 15 percent of its energy to heat. That may not seem like a high number, but it translates into a multi-billion dollar loss.

Scientists have looked at many solutions to increase energy efficiency, but Chakhalian seeks radical energy solutions, like a material that acts as a room-temperature superconductor.

“With a superconductor, you could redistribute energy around the globe with zero loss,” he said.

Room-temperature superconductivity remains a dream, but the findings of Chakhalian’s team may bring it closer to reality. Scientists have known for years that putting together two simple metals, semiconducting or ferroelectric materials of different sizes causes a strain that makes those materials stretch or compress to adjust the positions of atoms to match each other, often introducing defects and making them lose their ability to conduct electricity. This basic principle has been routinely applied to microelectronics devices used in everything from cell phones to computers to solar cells.

Until recently, many researchers believed the same principle applied to high temperature superconducting and other exotic electronic materials at the nanoscale. They believed that combining these materials under strain also would modify their metallic and superconducting properties and may turn into insulators.

Chakhalian and his colleagues, however, showed that in most cases, these previous beliefs were wrong.

“To our surprise, we found that with ultra-thin films of high-temperature superconductors and similar correlated electron oxides, you can perfectly match nanofilms to substrates without noticeable compressing or stretching the materials,” Chakhalian said. He and his colleagues conducted experiments at the synchrotron at Argonne National Laboratory on ultra-thin films of just a few atomic layers thick. With a technique Chakhalian perfected in past work published in Science magazine in 2007, scientists can “see” the stretching and compressing that takes place in most materials. However, with the novel electronic materials, the result markedly differed from past experience – the atoms “fit” perfectly and the nano-layers retained their shape.

“You can’t assume that nature behaves identically with different materials,” Chakhalian said.

Additionally, theorist James Rondinelli at Drexel University, conducted complex super-computer based calculations to determine why the material retains its atomic shape and unique properties. They found that, instead of stretching or compressing, the chemical bonds prefer to rotate to accommodate the strain.

“This opens the door to another whole class of materials and novel magnetic and superconducting phases,” Chakhalian said. Moreover, they discovered that the atomic level strain accommodation creates dramatically different properties depending on the direction of strain, in other words, whether the film is stretched or compressed.

“This gives us another degree of freedom,” Chakhalian said. “This is completely not symmetric, contrary to what everyone has anticipated for decades. And in nanofilms it may end up with absolutely different physics from the bulk crystals.”

This happens because the electrons in high-temperature superconducting and similar materials are keenly aware of one another. This awareness causes them to repel one another to the extreme, so compressing and stretching is not energetically easiest way. Instead, rotation of structural units works best.

“Nature is lazy. It does not want to expend energy,” Chakhalian said. “Now we can use these new-found properties as the foundation of the next generation of ultra-thin film technology with yet unknown functionalities.”

Chakhalian is the Charles and Clydene Scharlau Professor of Physics in the J. William Fulbright College of Arts and Sciences.

CONTACTS:
Jak Chakhalian, professor, physics
J. William Fulbright College of Arts and Sciences
479-575-4313, jchakal@uark.edu
Melissa Lutz Blouin, senior director of academic communications
University Relations
479-575-5555, blouin@uark.edu

Melissa Lutz Blouin | Newswise Science News
Further information:
http://www.uark.edu

More articles from Physics and Astronomy:

nachricht Witnessing turbulent motion in the atmosphere of a distant star
23.08.2017 | Max-Planck-Institut für Radioastronomie

nachricht Heating quantum matter: A novel view on topology
22.08.2017 | Université libre de Bruxelles

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

What the world's tiniest 'monster truck' reveals

23.08.2017 | Life Sciences

Treating arthritis with algae

23.08.2017 | Life Sciences

Witnessing turbulent motion in the atmosphere of a distant star

23.08.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>