Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Neutron Analysis Reveals 'Two Doors Down' Superconductivity Link

09.02.2011
Neutron scattering analysis of two families of iron-based materials suggests that the magnetic interactions thought responsible for high-temperature superconductivity may lie "two doors down": The key magnetic exchange pairings occur in a next-nearest-neighbor ordering of atoms, rather than adjacent atoms.

Researchers at the Department of Energy's Oak Ridge National Laboratory and the University of Tennessee, using the Spallation Neutron Source's ARCS Wide Angular Range Chopper Spectrometer, performed spin-wave studies of magnetically ordered iron chalcogenides. They based their conclusions on comparisons with previous spin-wave data on magnetically ordered pnictides, another class of iron-based superconductors.

"As we analyze the spectra, we find that even though the nearest neighbor exchange couplings between chalcogenide and pnictide atoms are different, the next nearest neighbor exchange couplings are closely similar," said Pengcheng Dai, who has a joint appointment with ORNL's Neutron Sciences Directorate and the University of Tennessee.

Dai referred to theories that have suggested second-nearest-neighbor couplings could be responsible for the widely acclaimed but poorly understood properties of high-temperature superconductors.

"There are theories suggesting that it’s the second nearest neighbor that drives the superconductivity," he said. "Our discovery of similar next-nearest-neighbor couplings in these two iron-based systems suggests that superconductivity shares a common magnetic origin."

Oliver Lipscombe of the University of Tennessee, Dai and ORNL's Doug Abernathy used the ARCS time-of-flight instrument on the SNS to study spin waves of the chalcogenide iron-tellurium superconductor and compared these with iron pnictide superconductors.

Scientists have been studying the iron-based superconductors since their discovery in 2008 to see if the dynamics behind their high-temperature superconducting properties -- in which electricity flows without resistance at temperatures well above absolute zero -- could help explain what was until recently thought to be exclusive to copper-oxide-based superconductors.

"Finding commonalities is always a good step when you’re looking for a very basic understanding of a phenomenon like high-temperature superconductivity," said Abernathy, who is lead instrument scientist for the ARCS instrument.

The team's neutron scattering analysis of the materials was made possible by the high intensity of the neutron beams provided by the SNS, which is the world's most powerful pulsed neutron source. Neutrons, which carry no electric charge but can act as subatomic magnets, are well suited for studying atom-scale spin characteristics.

"Since the interactions in the high-temperature superconductors are so strong, measurement of these materials’ spin waves requires beams of energetic neutrons that were unavailable to the research community at this intensity before the SNS," Abernathy said.

The work, which was funded by the DOE Office of Science, is published in Physical Review Letters.

ORNL is managed by UT-Battelle for the Department of Energy's Office of Science.

Image: http://www.ornl.gov/info/press_releases/photos/FeTe_spinwave.jpg

Caption: This visual representation of neutron data from ORNL's Spallation Neutron Source shows the evolution of spin waves as a function of increasing energy for the iron chalcogenide FeTe. Experiments indicate high-temperature superconductivity in different materials may share a common magnetic origin.

Bill Cabage | Newswise Science News
Further information:
http://www.ornl.gov/news

More articles from Materials Sciences:

nachricht New approach to revolutionize the production of molecular hydrogen
22.05.2017 | Technische Universität Dresden

nachricht Photocatalyst makes hydrogen production 10 times more efficient
19.05.2017 | Kobe University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

Im Focus: Using graphene to create quantum bits

In the race to produce a quantum computer, a number of projects are seeking a way to create quantum bits -- or qubits -- that are stable, meaning they are not much affected by changes in their environment. This normally needs highly nonlinear non-dissipative elements capable of functioning at very low temperatures.

In pursuit of this goal, researchers at EPFL's Laboratory of Photonics and Quantum Measurements LPQM (STI/SB), have investigated a nonlinear graphene-based...

Im Focus: Bacteria harness the lotus effect to protect themselves

Biofilms: Researchers find the causes of water-repelling properties

Dental plaque and the viscous brown slime in drainpipes are two familiar examples of bacterial biofilms. Removing such bacterial depositions from surfaces is...

Im Focus: Hydrogen Bonds Directly Detected for the First Time

For the first time, scientists have succeeded in studying the strength of hydrogen bonds in a single molecule using an atomic force microscope. Researchers from the University of Basel’s Swiss Nanoscience Institute network have reported the results in the journal Science Advances.

Hydrogen is the most common element in the universe and is an integral part of almost all organic compounds. Molecules and sections of macromolecules are...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

Innovation 4.0: Shaping a humane fourth industrial revolution

17.05.2017 | Event News

Media accreditation opens for historic year at European Health Forum Gastein

16.05.2017 | Event News

 
Latest News

New approach to revolutionize the production of molecular hydrogen

22.05.2017 | Materials Sciences

Scientists enlist engineered protein to battle the MERS virus

22.05.2017 | Life Sciences

Experts explain origins of topographic relief on Earth, Mars and Titan

22.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>