Energy News  
Exotic Materials Provide Insight Into Superconductivity

The compounds they've studied are made out of elements in the actinide series, including neptunium and plutonium.
by Staff Writers
New Brunswick NJ (SPX) Jul 28, 2008
Physicists at Rutgers and Columbia universities have gained new insight into the origins of superconductivity - a property of metals where electrical resistance vanishes - by studying exotic chemical compounds that contain neptunium and plutonium.

While superconductivity holds promise for massive energy savings in power transmission, and for novel uses such as levitating trains, today it occurs only at extremely cold temperatures. As a result, its use is now limited to specialized medical and scientific instruments. Over the past two decades, scientists have made metals that turn superconducting at progressively higher temperatures, but even those have to be cooled below the temperature of liquid nitrogen.

Still, physicists believe room temperature superconductivity may be possible. The work reported by the Rutgers and Columbia physicists is a step in that direction - shedding new light on the connection between magnetism and superconductivity.

"The exotic compounds we're studying will not become practical superconducting materials; however, by studying them we can learn the trends that govern a material's transition to superconductivity" said Piers Coleman, physics professor at Rutgers.

Coleman, along with Rutgers graduate student Rebecca Flint and Columbia postdoctoral research scientist Maxim Dzero, are publishing their findings in an upcoming issue of the journal Nature Physics. The compounds they've studied are made out of elements in the actinide series, including neptunium and plutonium. In these materials, active electrons are in "f-orbitals." In contrast, materials that make up today's highest-temperature superconductors, including copper or iron, have active electrons in "d-orbitals." The f-electron materials generally have lower superconducting temperatures than their d-electron counterparts; but they are easier to make and may be easier to understand.

"Electrons must bind together into pairs called 'Cooper pairs' for materials to become superconducting," Flint said. "In earlier studies, a small amount of magnetism was lethal to this pairing; however, in these materials, magnetism is not bad. It actually appears to play a central role in driving the pairing effect."

These new superconductors are part of a class of materials referred to as "heavy electron superconductors," metals that are filled with tiny, atomic-sized magnets known as "spins." When electrons pass through this forest of magnets, they slow down and move sluggishly as if they were extremely heavy.

"In most heavy electron superconductors, the electrons have to get heavy before they go superconducting," said Coleman. "But in the highest temperature versions, the electrons get heavy and become superconducting at the same time."

To understand this effect, the scientists have proposed a new type of electron pairing. "We've found that the electrons form much stronger pairs if they team up with one of the tiny atomic magnets - a combination that might be called a quantum-mechanical 'menage a trios,'" said Coleman. "The spin in the middle brings the pair of electrons close together, and a stronger pair means superconductivity at higher temperatures."

The scientists hope these ideas can be applied to d-electron materials, where the superconductivity may occur much closer to room temperature.

Community
Email This Article
Comment On This Article

Share This Article With Planet Earth
del.icio.usdel.icio.us DiggDigg RedditReddit
YahooMyWebYahooMyWeb GoogleGoogle FacebookFacebook



Related Links
Rutgers
Powering The World in the 21st Century at Energy-Daily.com



Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News


Closing The Hydrogen Economic Loop
Bloomfield Hills MI (SPX) Jul 28, 2008
The inventor of the nickel metal hydride (NiMH) technology used for building batteries for countless portable electronic gadgets and now hybrid gas-electric cars believes the hydrogen economy is already upon us.







  • China's largest oil and gas producer cuts jobs: state media
  • Workers struggle to clean up oil spill on Mississippi
  • Scientists work on garbage for gas
  • Researchers Generate Hydrogen Without The Carbon Footprint

  • Outside View: India nuke tango -- Part 1
  • Thorium Power Adds Nuclear Technology Experts
  • Australia looks positively at US-Indian nuclear deal
  • Malaysia looking at building its first nuclear plant: report

  • Air Monitoring Helps Anticipate Possible Ecosystem Changes
  • Air Travelers And Astronomers Could Benefit From Atmospheric Turbulence Research
  • NASA And Air Resources Board To Examine California Air Quality
  • Field Project Seeks Clues To Climate Change In Remote Atmospheric Region

  • WWF blasts EU's illegal wood imports, led by Finland
  • Scientists to discuss climate risk posed by wetlands destruction
  • Ancient Australian tree takes life-saving drive
  • Scattered Woodlands Complicate Forest's Response To Climate Change

  • Reclaimed Wastewater Benefits Florida's Citrus Orchards
  • UN chief calls for sharp hike in world farm output
  • Digital Cameras And Remote Satellites Measure Crop Water Demand
  • Pollination Habits Of Endangered Rice Revealed To Help Preservation

  • Fuel For Thought On Transport Sector Challenges
  • China unsold new car stock hits four-year high: report
  • SKorea's Ssangyong plans shutdown as SUV demand falls
  • China loses WTO car parts case against US

  • Russia And China May Co-Design New Passenger Plane
  • China Southern Airlines managers take paycut due to oil prices
  • Air China says it is to buy 45 Boeing aircraft
  • British PM blasts polluting 'ghost' flights

  • Nuclear Power In Space - Part 2
  • Outside View: Nuclear future in space
  • Nuclear Power In Space

  • The content herein, unless otherwise known to be public domain, are Copyright 1995-2007 - SpaceDaily.AFP and UPI Wire Stories are copyright Agence France-Presse and United Press International. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by SpaceDaily on any Web page published or hosted by SpaceDaily. Privacy Statement