Nanotechnology Now

Our NanoNews Digest Sponsors







Heifer International

Wikipedia Affiliate Button


Home > Press > Pinning Down Superconductivity to a Single Layer

This graphic shows the inside of the molecular beam epitaxy chamber where thin films are built layer by layer, showing an artists rendition of the film synthesis process.
This graphic shows the inside of the molecular beam epitaxy chamber where thin films are built layer by layer, showing an artists rendition of the film synthesis process.

Abstract:
Findings may lead to precision engineering of superconducting thin films for electronic devices

Pinning Down Superconductivity to a Single Layer

Upton, NY | Posted on October 30th, 2009

Using precision techniques for making superconducting thin films layer-by-layer, physicists at the U.S. Department of Energy's (DOE) Brookhaven National Laboratory have identified a single layer responsible for one such material's ability to become superconducting, i.e., carry electrical current with no energy loss. The technique, described in the October 30, 2009, issue of Science, could be used to engineer ultrathin films with "tunable" superconductivity for higher-efficiency electronic devices.

"We wanted to answer a fundamental question about such films," said Brookhaven physicist and the group leader Ivan Bozovic. "Namely: How thin can the film be and still retain high-temperature superconductivity?"

The thinner the material (and the higher its transition temperature to a superconductor), the greater its potential for applications where the superconductivity can be controlled by an external electric field. "This type of control is difficult to achieve with thicker films, because an electric field does not penetrate into metals more than a nanometer or so," Bozovic explained.

To explore the limits of thinness, Bozovic's group synthesized a series of films based on the high-temperature superconducting cuprates (copper-oxides) — materials that carry current with no energy loss when cooled below a certain transition temperature (Tc). Since zinc is known to suppress the superconductivity in these materials, the scientists systematically substituted a small amount of zinc into each of the copper-oxide layers. Any layer where the zinc's presence had a suppressing effect would be clearly identified as essential to superconductivity in the film.

"Our measurements showed that the zinc doping had essentially no effect, except when placed in a single, well-defined layer. When the zinc was in that layer, the superconductivity was dramatically suppressed," Bozovic said.

The material studied by Bozovic's team was unusual in that it consists of layers of two materials, one metallic and one insulating, that are not superconductors on their own, but rather exhibit superconductivity at the interface between them.

The layer identified as essential to the superconductivity by the zinc-substitution experiment represents the second copper-oxide layer away from the interface. The scientists found that the presence of zinc had no effect on the transition temperature at which superconductivity sets in, about 32 kelvin (-241 Celsius), except when placed in that particular layer. In the latter case, the scientists observed a dramatic drop in the transition temperature to 18 kelvin (-255 Celsius). The reduction in transition temperature provides a clear indication that that particular layer is the "hot" one responsible for the relatively high temperature at which superconductivity normally sets in for this material.

"We now have a clean experimental proof that high-temperature superconductivity can exist, undiminished, in a single copper-oxide layer," Bozovic said. "This piece of information gives important input to our theoretical understanding of this phenomenon."

Bozovic explained that, in the material he studied, the electrons required for superconductivity actually come from the metallic material below the interface. They leak into the insulating material above the interface and achieve the critical level in that second copper-oxide layer.

But in principle, he says, there are other ways to achieve the same concentration of electrons in that single layer, for example, by doping achieved by applying electric fields. That would result in high-temperature superconductivity in a single copper-oxide layer measuring just 0.66 nanometers.

From a practical viewpoint, this discovery opens a path toward the fabrication of electronic devices with modulated, or tunable, superconducting properties which can be controlled by electric or magnetic fields.

"Electronic devices already consume a large fraction of our electricity usage — and this is growing fast." Bozovic continued. "Clearly, we will need less-power hungry electronics in the future." Superconductors, which operate without energy loss — particularly those that operate at warmer, more-practical temperatures — may be one way to go.

Bozovic's layer-by-layer synthesis method and ability to strategically alter individual layers' composition might also be used to explore and possibly control other electronic phenomena and properties that emerge at the interfaces between layered materials.

This research was funded by the DOE Office of Science.

####

About Brookhaven National Laboratories
One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE's Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

For more information, please click here

Contacts:
Karen McNulty Walsh
(631) 344-8350

Mona S. Rowe
(631) 344-5056

Copyright © Brookhaven National Laboratories

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related News Press

Physics

Kinks and curves at the nanoscale: New research shows 'perfect twin boundaries' are not so perfect May 20th, 2013

Scientists capture first direct proof of Hofstadter butterfly effect May 17th, 2013

RUB physicists let magnetic dipoles interact on the nanoscale for the first time: 'Of great technical interest for future hard disk drives' May 15th, 2013

New principle may help explain why nature is quantum May 15th, 2013

News and information

Kinks and curves at the nanoscale: New research shows 'perfect twin boundaries' are not so perfect May 20th, 2013

Aspen Aerogels Announces $22.5 Million Private Placement May 18th, 2013

NanoInk, Inc. Assets To Be Sold May 18th, 2013

Artificial Forest for Solar Water-Splitting: Berkeley Lab Researchers Report First Fully Integrated Artificial Photosynthesis Nanosystem May 17th, 2013

Thin films

Moth-Inspired Nanostructures Take the Color Out of Thin Films May 17th, 2013

Govt.-Legislation/Regulation/Funding/Policy

Kinks and curves at the nanoscale: New research shows 'perfect twin boundaries' are not so perfect May 20th, 2013

Beautiful "flowers" self-assemble in a beaker: Elaborate nanostructures blossom from a chemical reaction perfected at Harvard May 17th, 2013

Artificial Forest for Solar Water-Splitting: Berkeley Lab Researchers Report First Fully Integrated Artificial Photosynthesis Nanosystem May 17th, 2013

Moth-Inspired Nanostructures Take the Color Out of Thin Films May 17th, 2013

Possible Futures

Lifeboat publishes its first book: The Lifeboat Foundation has published its first book, "The Human Race to the Future: What Could Happen -- and What to Do" May 14th, 2013

UC Santa Barbara History Professor's Book Elucidates, Celebrates ‘Visioneers' May 14th, 2013

Conceptual Nanomedical Lipofuscin Removal Strategy April 29th, 2013

The Global Desalination Market 2013-2023 April 24th, 2013

Chip Technology

UC Riverside scientists discovering new uses for tiny carbon nanotubes: Adding ionic liquid to nanotube films could build smaller gadgets, and create more cost effective 'Smart Windows' that darken in bright sun May 15th, 2013

Nanometrics Announces Upcoming Investor Events May 14th, 2013

HELIOS Program Develops Complete Supply Chain for Integrating Photonics with CMOS Circuit via IC Fabrication Processes May 14th, 2013

Silex Microsystems Joins ENIAC Project PROMINENT To Bring Flexible and Cost Effective Inkjet Technologies to the MEMS Manufacturing Process: Silex Will Develop New Solutions for Through-Silicon Via Manufacture and Hermetic Wafer Bonding May 13th, 2013

Nanoelectronics

Imec and Renesas collaborate on ultra-low power short range radios: Collaboration will develop robust wireless solutions for future electronics May 16th, 2013

Piezoelectric 'taxel' arrays convert motion to electronic signals for tactile imaging April 25th, 2013

Battery and Memory Device in One April 25th, 2013

Secret of the Crystal's Corners: New Nanowire Structure Has Potential to Increase Semiconductor Applications: University of Cincinnati research describes discovery of a new structure that is a fundamental game changer in the physics of semiconductor nanowires April 23rd, 2013

Discoveries

Kinks and curves at the nanoscale: New research shows 'perfect twin boundaries' are not so perfect May 20th, 2013

Beautiful "flowers" self-assemble in a beaker: Elaborate nanostructures blossom from a chemical reaction perfected at Harvard May 17th, 2013

Artificial Forest for Solar Water-Splitting: Berkeley Lab Researchers Report First Fully Integrated Artificial Photosynthesis Nanosystem May 17th, 2013

Scientists capture first direct proof of Hofstadter butterfly effect May 17th, 2013

Announcements

Kinks and curves at the nanoscale: New research shows 'perfect twin boundaries' are not so perfect May 20th, 2013

Aspen Aerogels Announces $22.5 Million Private Placement May 18th, 2013

NanoInk, Inc. Assets To Be Sold May 18th, 2013

Scientists capture first direct proof of Hofstadter butterfly effect May 17th, 2013

NanoNews-Digest
The latest news from around the world, FREE





  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More












ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project








abbigliamento uomo
Computer Accessories
© Copyright 1999-2013 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE