Featured Research

from universities, journals, and other organizations

Roller coaster superconductivity discovered

Date:
August 18, 2010
Source:
Carnegie Institution
Summary:
Superconductors are more than 150 times more efficient at carrying electricity than copper wires. But these materials have to be cooled below an extremely low, so-called transition temperature for electrical resistance to disappear. Researchers have unexpectedly found that the transition temperature can be induced under two different intense pressures in a three-layered bismuth oxide crystal. They believe this unusual two-step phenomena comes from competition of electronic behavior in different layers.

This graphic shows the crystal structure of three-layered bismuth oxide.
Credit: Xiao-Jia Chen

Superconductors are more than 150 times more efficient at carrying electricity than copper wires. However, to attain the superconducting state, these materials have to be cooled below an extremely low, so-called transition temperature, at which point normal electrical resistance disappears. Developing superconductors with higher transition temperatures is one of physics' greatest quests.

Now, researchers at the Carnegie Institution's Geophysical Laboratory, with colleagues, have unexpectedly found that the transition temperature can be induced under two different intense pressures in a three-layered bismuth oxide crystal referred to as "Bi2223." The higher pressure produces the higher transition temperature. They believe this unusual two-step phenomena comes from competition of electronic behavior in different kinds of copper-oxygen layers in the crystal.

The work is published in the August 19, 2010, issue of Nature.

Until now, copper-laden materials called cuprates have been the only superconductors whose transition temperatures are higher than the liquid nitrogen boiling point at -321F (77 K). Whether researchers can make transition temperatures higher in such materials remains a challenge.

"Bi2223 is like a layered cake," explained lead author Xiao-Jia Chen at Carnegie. "On the top and bottom there are insulating bismuth-oxide layers. On the inside of those, come layers of strontium oxide. Next, are layers of copper oxide, then calcium, and finally the middle is another copper-oxide layer. Interestingly, the outermost and inner layers of copper oxide have different physical properties resulting in an imbalance of electric charge between the layers."

One way scientists have found to increase the transition temperature of superconducting materials is to "dope" them by adding charged particles.

Under normal pressure, the optimally doped Bi2223's transition temperature is -265F (108K). The scientists subjected doped crystals of the material to a range of pressures up to 359,000 times the atmospheric pressure at sea level (36.4 Giga Pascal), the highest pressure yet for magnetic measurements in cuprate superconductors. The first higher transition temperature happened at 100,666 atmospheres (10.2 GPa).

"After that, increasing pressures ended up with lower transition temperatures," remarked Chen. "Then to our complete surprise at about 237,000 atmospheres (24 GPa) the superconducting state reappeared. Under even more pressure, 359,000 atmospheres, the transition temperature rose to -215F (136K). That was the highest pressure our measuring system could detect."

Other research has shown that some multilayered superconducting materials like this one exhibit different electronic and vibrational behaviors in different layers. The researchers think that 237,000 atmospheres might be a critical point where pressure suppresses one behavior and enhances superconductivity.

"The finding gives new perspectives on making higher transition temperature in multilayer cuprate superconductors. The research may offer a promising way of designing and engineering superconductors with much higher transition temperatures at ambient conditions," concluded coauthor Viktor Struzhkin also of Carnegie.

The research was supported by the U. S. Department of Energy, Carnegie Canada, and the National Natural Science Foundation of China.

This work was conducted in collaboration with researchers at the South China University of Technology and Max Plank Institute for Solid State Research in Germany.


Story Source:

The above story is based on materials provided by Carnegie Institution. Note: Materials may be edited for content and length.


Journal Reference:

  1. Xiao-Jia Chen, Viktor V. Struzhkin, Yong Yu, Alexander F. Goncharov, Cheng-Tian Lin, Ho-kwang Mao, Russell J. Hemley. Enhancement of superconductivity by pressure-driven competition in electronic order. Nature, 2010; 466 (7309): 950 DOI: 10.1038/nature09293

Cite This Page:

Carnegie Institution. "Roller coaster superconductivity discovered." ScienceDaily. ScienceDaily, 18 August 2010. <www.sciencedaily.com/releases/2010/08/100818131557.htm>.
Carnegie Institution. (2010, August 18). Roller coaster superconductivity discovered. ScienceDaily. Retrieved September 15, 2014 from www.sciencedaily.com/releases/2010/08/100818131557.htm
Carnegie Institution. "Roller coaster superconductivity discovered." ScienceDaily. www.sciencedaily.com/releases/2010/08/100818131557.htm (accessed September 15, 2014).

Share This



More Matter & Energy News

Monday, September 15, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Frustration As Drone Industry Outpaces Regulation In U.S.

Frustration As Drone Industry Outpaces Regulation In U.S.

Newsy (Sep. 14, 2014) U.S. firms worry they’re falling behind in the marketplace as the FAA considers how to regulate commercial drones. Video provided by Newsy
Powered by NewsLook.com
Smart Gun Innovators Fear Backlash From Gun Rights Advocates

Smart Gun Innovators Fear Backlash From Gun Rights Advocates

Newsy (Sep. 14, 2014) Winners of a contest for smart gun design are asking not to be named after others in the industry received threats for marketing similar products. Video provided by Newsy
Powered by NewsLook.com
Scientists Have Captured The Sound Of An Atom

Scientists Have Captured The Sound Of An Atom

Newsy (Sep. 12, 2014) Scientists have captured the sound of a single atom by measuring its vibrations. We can't hear it, but it's reportedly the faintest sound possible. Video provided by Newsy
Powered by NewsLook.com
Solar Flare Surges Off Sun

Solar Flare Surges Off Sun

Reuters - US Online Video (Sep. 11, 2014) NASA captures video of a significant flare surging off the sun. Jillian Kitchener 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:
from the past week

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