Featured Research

from universities, journals, and other organizations

Engineering materials for super-efficient nanoelectronics: Potential way to make graphene superconducting

Date:
March 20, 2014
Source:
DOE/SLAC National Accelerator Laboratory
Summary:
Scientists have discovered a potential way to make graphene -- a single layer of carbon atoms with great promise for future electronics -- superconducting, a state in which it would carry electricity with 100 percent efficiency.

Adding calcium atoms (orange spheres) between graphene planes (blue honeycomb) creates a superconducting material called CaC6. Now a study at SLAC has shown for the first time that graphene is a key player in this superconductivity: Electrons scatter back and forth between the graphene and calcium layers, interact with natural vibrations in the material's atomic structure and pair up to conduct electricity without resistance.
Credit: Greg Stewart/SLAC

Scientists at the Department of Energy's SLAC National Accelerator Laboratory and Stanford University have discovered a potential way to make graphene -- a single layer of carbon atoms with great promise for future electronics -- superconducting, a state in which it would carry electricity with 100 percent efficiency.

Related Articles


Researchers used a beam of intense ultraviolet light to look deep into the electronic structure of a material made of alternating layers of graphene and calcium. While it's been known for nearly a decade that this combined material is superconducting, the new study offers the first compelling evidence that the graphene layers are instrumental in this process, a discovery that could transform the engineering of materials for nanoscale electronic devices.

"Our work points to a pathway to make graphene superconducting -- something the scientific community has dreamed about for a long time, but failed to achieve," said Shuolong Yang, a graduate student at the Stanford Institute of Materials and Energy Sciences (SIMES) who led the research at SLAC's Stanford Synchrotron Radiation Lightsource (SSRL).

The researchers saw how electrons scatter back and forth between graphene and calcium, interact with natural vibrations in the material's atomic structure and pair up to conduct electricity without resistance. They reported their findings March 20 in Nature Communications.

Graphite Meets Calcium

Graphene, a single layer of carbon atoms arranged in a honeycomb pattern, is the thinnest and strongest known material and a great conductor of electricity, among other remarkable properties. Scientists hope to eventually use it to make very fast transistors, sensors and even transparent electrodes.

The classic way to make graphene is by peeling atomically thin sheets from a block of graphite, a form of pure carbon that's familiar as the lead in pencils. But scientists can also isolate these carbon sheets by chemically interweaving graphite with crystals of pure calcium. The result, known as calcium intercalated graphite or CaC6, consists of alternating one-atom-thick layers of graphene and calcium.

The discovery that CaC6 is superconducting set off a wave of excitement: Did this mean graphene could add superconductivity to its list of accomplishments? But in nearly a decade of trying, researchers were unable to tell whether CaC6's superconductivity came from the calcium layer, the graphene layer or both.

Observing Superconducting Electrons

For this study, samples of CaC6 were made at University College London and brought to SSRL for analysis.

"These are extremely difficult experiments," said Patrick Kirchmann, a staff scientist at SLAC and SIMES. But the purity of the sample combined with the high quality of the ultraviolet light beam allowed them to see deep into the material and distinguish what the electrons in each layer were doing, he said, revealing details of their behavior that had not been seen before.

"With this technique, we can show for the first time how the electrons living on the graphene planes actually superconduct," said SIMES graduate student Jonathan Sobota, who carried out the experiments with Yang. "The calcium layer also makes crucial contributions. Finally we think we understand the superconducting mechanism in this material."

Although applications of superconducting graphene are speculative and far in the future, the scientists said, they could include ultra-high frequency analog transistors, nanoscale sensors and electromechanical devices and quantum computing devices.


Story Source:

The above story is based on materials provided by DOE/SLAC National Accelerator Laboratory. Note: Materials may be edited for content and length.


Journal Reference:

  1. S.-L. Yang, J. A. Sobota, C. A. Howard, C. J. Pickard, M. Hashimoto, D. H. Lu, S.-K. Mo, P. S. Kirchmann, Z.-X. Shen. Superconducting graphene sheets in CaC6 enabled by phonon-mediated interband interactions. Nature Communications, 2014; 5 DOI: 10.1038/ncomms4493

Cite This Page:

DOE/SLAC National Accelerator Laboratory. "Engineering materials for super-efficient nanoelectronics: Potential way to make graphene superconducting." ScienceDaily. ScienceDaily, 20 March 2014. <www.sciencedaily.com/releases/2014/03/140320101318.htm>.
DOE/SLAC National Accelerator Laboratory. (2014, March 20). Engineering materials for super-efficient nanoelectronics: Potential way to make graphene superconducting. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/2014/03/140320101318.htm
DOE/SLAC National Accelerator Laboratory. "Engineering materials for super-efficient nanoelectronics: Potential way to make graphene superconducting." ScienceDaily. www.sciencedaily.com/releases/2014/03/140320101318.htm (accessed October 24, 2014).

Share This



More Matter & Energy News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Police Testing New Gunfire Tracking Technology

Police Testing New Gunfire Tracking Technology

AP (Oct. 24, 2014) A California-based startup has designed new law enforcement technology that aims to automatically alert dispatch when an officer's gun is unholstered and fired. Two law enforcement agencies are currently testing the technology. (Oct. 24) Video provided by AP
Powered by NewsLook.com
3D Printed Instruments Make Sweet Music in Sweden

3D Printed Instruments Make Sweet Music in Sweden

Reuters - Innovations Video Online (Oct. 23, 2014) Students from Lund University's Malmo Academy of Music are believed to be the world's first band to all use 3D printed instruments. The guitar, bass guitar, keyboard and drums were built by Olaf Diegel, professor of product development, who says 3D printing allows musicians to design an instrument to their exact specifications. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Chameleon Camouflage to Give Tanks Cloaking Capabilities

Chameleon Camouflage to Give Tanks Cloaking Capabilities

Reuters - Innovations Video Online (Oct. 22, 2014) Inspired by the way a chameleon changes its colour to disguise itself; scientists in Poland want to replace traditional camouflage paint with thousands of electrochromic plates that will continuously change colour to blend with its surroundings. The first PL-01 concept tank prototype will be tested within a few years, with scientists predicting that a similar technology could even be woven into the fabric of a soldiers' clothing making them virtually invisible to the naked eye. Matthew Stock reports. Video provided by Reuters
Powered by NewsLook.com
Jet Sales Lift Boeing Profit 18 Pct.

Jet Sales Lift Boeing Profit 18 Pct.

Reuters - Business Video Online (Oct. 22, 2014) Strong jet demand has pushed Boeing to raise its profit forecast for the third time, but analysts were disappointed by its small cash flow. Fred Katayama reports. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Space & Time

Matter & Energy

Computers & Math

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins